Nice trick, I have seen a similar effect performed with 2 decks, but I've not seen a version using two halves of 1 deck.
One thing I did notice at the start of the trick was that you kept flashing the bottom card. I'm not sure whether there is a reason for this or not. I figured probably not, but its a bad habit to get into doing things like that. If you were using that as a key card in some way, and you were trying to glimpse it, I'd advise you to do so more discreetly - when picking the cards off the table, or even better - when taking them out of the box. I also noticed the same card flash several times during your shuffles and it stayed in the same position - these kinds of things can arouse suspicion in your spectators - regardless of whether that card was actually important, it made it seem to me that it was quite likely that your shuffles were false in some way.
If it is just a habit of yours I'd advise trying not to do it. It makes you seem nervous, when really you want to come across to the spectator like you are a complete natural with the cards, and little ticks like that (another one is incessantly ruffling the cards for no reason- one that a lot of magicians seem to do) don't give that impression.
The other thing I would say is not to use that false cut flourish thing you did in the middle. This is mainly a personal thing for me - but I am never convinced by them. No one ever cuts cards like that, so the instant I see it I think 'false cut'. It's a nice skill to have, and cool to show off, but I would do it at stages in your routine where it doesn't form a part of the trick - between tricks for example. Otherwise (I understand I can't speak for everyone) it just seems suspicious. The best false cuts are the ones that look like how it does when you might cut the deck in a regular fashion in my opinion.
Hope that helps
Laurens
