This is my honest opinion on this effect, it may clash with all the 5 star reviews but I will tell you why I think it is only worth 3 stars.

The process to get to the pay off is very process driven, if you are performing for a drunken audience forget doing this trick. Matt was doing this at a bar and the lady on the second clip of trailer was very much the worst for wear. If you end up buying the download you will know fully what I mean.

In order to perform the trick as shown on the trailer, you need to know something about the coins. Matt does explain how you can perform it with the spectators coins, making it more impromptu but this can cause problems in getting to the outcome. It could also make it more transparent
to what you need to know and do.

If you are willing to put the time and effort in to carrying a purse of change or other objects around with you and you perform on a table top and the audience is paying attention this could be a nice effect for you.

However if the audience have been drinking and don’t follow your instructions to the letter, drop coins etc you will have a difficult time getting to a pay off prediction that they might not understand.
I personally don’t think the final reveal of the prediction is strong enough IMHO and due to the performing conditions it is not a worker for me.

Rarely is there a true, easy to do, mind blower that fills time and is spectator centric. This is a mind blower. It is impossible for the spec to figure out. You can't do it with drunks, but in settings where you ahve intelligent spectators (the smarter and more educated the better for this one) this is a reputation maker. It is an adaptation of an old trick. One with cards I used to do years ago. Seeing this demo I didn't link the two. Matt has a great presentation and this feels so fair to the audience. For the Magi there is nothing difficult to learn to do. No gaffs and no prep needed. That said the secret is dastardly and you'll fool yourself. I think Matt missed an important thing, however, which I'm adding here for those of you who get the trick. The WOW factor lies (for me) in having the spectators exchange coins WITHOUT THE MAGICIAN SEEING WHICH ARE BEIGN EXCHANGED! Don't let spec 1 hand 4 of his coins to spec 2 openly. Make a HUGE deal about having spec 1 roll the die, then taking that number and NOT SHOWING THE MAGI WHICH COINS ARE BEING GIVEN TO SPEC 2 give those to Spec two. Each transfer should be hidden form the magi. the final reveal recap is that You could have no way to influence the outcome as you never knew WHICH coins were being given from 1 to 2 or from 2 to 1. They just rolled die and secretly moved coins. So how could you control the outcome if you didn't know is quarters or dines or pennies were being moved???? So much stronger this way. Hope this helps!

I can see how this might be a cool thing to do when you are sitting around and have plenty of time. For working, at least at the places I work close-up or walk-around, this is just too slow.
I'm not saying that it is not amazing. I'm sure that the person who is mathematically minded will be up at night over this. I can also see an average spectator just saying "it's math." That's not fair, but that's what happens.
I think that this would be best in a late night session with some very intelligent people who have time to watch and pay attention. For most of those whom I perform for, I'd do three or four pieces in the time this takes.
It's a fascinating principle and a good story, just not for me. Your mileage may vary.

Hive Mind is a very fresh and well thought approach to that principle. It seems impossible but will always work. I love the handling when the audience writes the prediction. Matt Baker has done a really good job not alone on the trick but also on the explanation. The principle is so counter intuitive and deceptive that his excellent explanation really is helps to break it down clearly. Hive Mind has all the important parts a good trick needs:
-Audience participation
-Easy presentation
-Impromptu
Deserves 5 stars!

New presentation on a time-tested principle. Matt clearly presents and explains his entertaining and mystifying take on Bob Hummer's mathematical based card trick.

Matt's touches and presentation ideas add intrigue and interest. The spectators remain clear at all times what's happening and the seeming randomness to the proceedings.

I liked the effect. It's totally impromptu which I love. You just need time, space and a quiet enough setting to keep it all clear to the spectators.

Nicely done!

No moves, no switches, no palms, no shells, no gimmicks. Even the one pivotal element has a number of what I'd call "just in case" workarounds.

Baker's presentation seems oh so hands-off, and truly makes it look like the spectators are in full control of the big payoff here. And in a way: they actually are.

As a mentalist routine it plays really well with Baker's 'Mind Hive' patter (and yes, he does pay proper homage to the origins of this trick). Can be done with coins, candy, cards - you name it.

Impromptu. Completely impromptu.
Is this worth it?
Oh yes....

This has to be one of the best mentalism releases in the past few years. Loving the method and the instruction given by Matt. If you love blowing away groups of people, this is the trick for you.

Wonderful download buy it now!

Impromptu, anywhere, anytime. Use your coins, their borrowed coins or even colored candy … what more could you want.This trick really seems impossible because the spectators seemingly make all the decisions. Matt does a great job of explaining the theory of the trick and overcoming certain situations that may arise using the spectators coins. You may have to watch the video a fews times but you will get it. You could use cards but I’m sure you already do a lot of card tricks so this is a nice change of pace. I think I will use colored wrapped candies (won’t be messy) as it will be a great organic trick and something different. If you use your business card for the prediction, this is other great way of marketing yourself. They will certainly remember you and the trick.

This is a fantastic trick. I'm usually not a fan of math tricks but this one is very different. It totally doesn't feel like a math trick and the fact that they write the prediction is so disarming. It is hypothetically impromptu and you can do this with everything borrowed although if you really want to do this you should probably carry around your own change just in case. Most people don't have enough change on their own and I haven't found spectators being too eager to pool their cash together.

There is a slight risk that your first spectator make take a completely wrong number of coins and then the way to take care of that can hypothetically not go nearly as planned and end up seeming very forced, but if you have a decent amount of experience performing you shouldn't need to worry about it. I would not recommend this trick to anyone who doesn't have significant practice performing in front of real audiences otherwise their directions won't seem inconsequential enough. (I'm sorry if that doesn't make so much sense. I'm trying to avoid anything that can be a tip-off to the method.)

This method is a lot of fun and there are a lot of layers to this. It's really hard to deconstruct. You'll have a lot of fun doing this.

Honestly, this routine is too PROCESS HEAVY for my taste.

What do I mean by process? It's the unentertaining things we must do in order to make a miracle. The counting, the imaginary dice, crayon and paper writing, the questioning, instructing "So write 'quarters and dimes' under Spectator # 1's coins...", etc.

It's lots and lots of boring setup before you get to the finale. Unlike with more visual magic tricks, people have to follow from start to finish to appreciate. Too much going on. So much that people may believe that, somehow, something in all that process enabled the outcome.

Now, if you have the chops to streamline this routine so either the processes themselves are shortened or perhaps overlapped or covered with other dialogue or made fun through humor, this one can be a close-up killer.