Regal makes this point very well in the explanation, but it is worth repeating. Done well, this is an miracle that the spectators will remember for a long time.
While it takes a little bit of preparation, and practice of what can be a difficult move, this is a perfect place to practice this move. Some tricks lend themselves to "on the job" practice. That's how I learned the top-change. This is a piece that will allow you to practice the bottom deal from a very small packet (the easiest way) under pressure. I have not seen an effect better suited to learning this move.
But the thing is that this is a great trick. In addition to allowing you to learn a move and do it under pressure, it is a trick that will KILL under the right conditions. This is not the trick to do when you are in a hurry and have very limited time with each group. This is a piece for the end of the night when things have slowed down and you want to impress a small group (hopefully including the booker).
Highly recommended for a number of reasons. Don't pass this by, it's too good.

BTW, David, SLAP

This is a really jarring effect! I love “what are the odds?” kind of tricks, but Symmetry is seriously one of my favorites because the spectator REALLY DOES have a TOTALLY FREE choice! You are NOT forcing any cards on them!

There is a gimmick involved, but it’s invisible and takes no skill and about 10 minutes to make. There are only two very simple moves, so this is great for beginners, too.

David teaches a simple little bonus effect at the beginning of the video to introduce the method and concept, and it’s a great little trick on its own, that can be performed with any borrowed deck.

Symmetry reminds me of other effects that require much more advanced sleight of hand skills. So if you’re not a move-monkey, you might want to give this one a try.

I also like that this can play so well as a magic trick or a mentalism effect.

This is a great effect. Anytime you can get away from the standard "pick a card" trick, you make the other stuff you do even stronger so, for me, this is worth learning. However, I don't agree with the reviewers who say this is "easy" or only requires "minimal sleights." I have been doing card magic semi-professionally for nearly 40 years; I have never needed and therefore never learned the one critical sleight needed here. I understand that practice is always a requisite but, IMHO, Regal glosses over the mechanics and many, like me, will need to find another tutorial to thoroughly understand it and get it working. Hence, I am rating this four stars. Having said that, if you're willing to put in the extra effort this is a very strong effect to learn and perform.

I really like David’s pace that he performed at, and by this I mean everything is slow enough for everyone to totally understand what is going on , and at the same time the micro movements needed here are masked
COMPLETELY.
A utility move is also taught here and again this is expert advice & tuition, and goes completely under the radar

Full disclosure: I received a free copy of this trick with a request to write a review. With that out of the way:

This effect is an excellent one. Very clean coincidence effect, instant reset (if you want: see below), easy to do and looks super clean (because it mostly is). This is the type of trick that gets great redactions.

However, I have a couple of complaints with this download, although neither of them are with the trick itself, but rather with the presentation of the trick.

First: the advertising demo seemed to give me the impression that there is nothing special about the deck. This isn't entirely true, there is 'something' that needs to be done with the deck in advance, and while technically you could go ahead and use the deck as a regular deck when you're done with this trick, you probably wouldn't want to (will make reset a pain). The deck is still examinable (after the trick is done), but you'll need to do a reset afterwards if you want to preform this trick again.

Second complaint I have: there is one scenario that could come up which throws the trick for a slight loop. Now, it doesn't entirely derail the trick (as a matter of fact, that scenario came up in one of the demo performances and David still completed the trick spectacularly), but should still warrant some mention in the explanation. As I was watching the explanation, I was expecting David to mention this scenario near the end, and was disappointed when it wasn't mentioned. Now, it's not too difficult to work around this issue (I thought up two possible simple workarounds while writing this review), but I feel it should have been mentioned in the explanation, since otherwise it is slightly incomplete.

Otherwise, the teaching, as David's teaching usually is, is excellent.

In summary:

Pros:
Super strong effect
Spectator has free choice
Easy reset (if you don't have the deck out for examination or use it for another trick)
Everything is examinable after the fact, if you don't want to reset.

Cons:
Requires a minimal amount of pre-work to set up the deck
Tedious reset if you don't use the easy reset method
Very slight amount of explanation is lacking
I don't like the demo video

In conclusion: the trick itself would warrant 5 stars, and the fact that the only real gripes I have are somewhat tangential can attest to the strength of the trick. However,I can't disregard my two main concerns, so that brings my score down a bit to what would probably be somewhere between 3 and 4 stars, so I'm rounding up to 4.

Great trick if your hands' aren't arthritic.

Look, David Regal is great. And clever. But the trailer and reviews made this seem like something I would use, something practical. To me, it is not.

Any time you buy something Regal puts out, you’re going to learn something, but this my-star rating is intended to counteract the reviews that are tripping over themselves to say how great “Symmetry” is. I just don’t get it.

Long and short of it, you’re going to have to reorder the cards (not hard) and then put some work into 26 of ‘em. I guess it’s clever but to me it’s not as practical or elegant as the description made it seem. No disrespect to D.R. or others who enjoyed it, but in the case of “Symmetry” I think at least one minority report is called for.

I have found that I love Regals tricks. While there is sometimes “gimmicks” needed, this one isn’t really a gimmick at all. Just prep. I love the ease of the performance and the fact that I don’t have to destroy or add any extra cards or take away from my decks ability to play games and etc with them. They still stay perfectly usable and that’s why this gets another 5 star from me. Get it!!

I have found that I love Regals tricks. While there is sometimes “gimmicks” needed, this one isn’t really a gimmick at all. Just prep. I love the ease of the performance and the fact that I don’t have to destroy or add any extra cards or take away from my decks ability to play games and etc with them. They still stay perfectly usable and that’s why this gets another 5 star from me. Get it!!

...but not a great trick. Although it has potential. It's clever: that's for sure. A really clever idea. And it's a good plot.

You'll need a dedicated deck in a simple set-up. You can perform anything you like with it afterwards, but unless you do this trick first, you'll have to ring it in.

Perhaps it's David Regal's delivery? Don't get me wrong: I LOVE David Regal, but this trick is, I feel, better suited to a slower mysterious presentation than Regal's whimsical, jokey style.