Having had a chance to look at all of these, I think the Hex handle is interesting, and will be interesting to see what difference it really makes. I know of a number of makers who have been playing with handles and this is something a bit different again.
I remember the TAS inserts as there was a lot of discussion on here about them some time ago. While I know it is claimed that this makes the bat a grade B, I'm not so sure that the MCC will retain that, especially as the purpose is to improve the performance of the bat, which we all know they don't like... It's an interesting idea all the same and I'd like to try it out.
The "Double Spine" looks like a way to create a wider spine without increasing the weight. Again, remains to be seen whether it makes that much difference, but I'd like to have a go.
The V12 is, for me, the biggest disappointment, taking the V12 of a couple of years ago and sticking retro stickers on it rather than following what GN did and creating an update on a classic shape. That sucks in my opinion.
I'm also a bit disappointed with the naming of the new bat. I have an original V1200 at home. It was a V12 with an extended hump to give ti more middle. Come on Slazenger. If you are going to release bats using old names, at least pay homage...