hey man, i havent tried the evo, but i have owned last years SL. i currently own a 2011 batazion (basically an evil twin w/sintered base).
both NS's RC design and bataleons TBT achieve the same things, just in different manners. both can be catch free, poppy, etc but i feel it depends on where you place most of your emphasis. for example tbt is most catch free at the edges by the tip and tail while the RC is most catch free in between ur feet.
because of this, i really think it comes down to personal preference. i know thats not what you like to hear, but i do think its true. i think both boards will be great for your style, but whether you'll like TBT over RC will be up to you.
also, let me say that while i was impressed with the skatey feel of the RC, i did not like it on edge, and much prefer regular cambers edge hold. i am from boston, i know nothing but ice. ill take the grip of a positive camber over vario grip on a RC board any day, but id say its more because its what im most comfortable on. this was the reason why i sold my SL and stuck with my bataleon. and the bataleon on ice holds just fine.
theres so many new techs out there that i wanna try, but i narrowed mine down to RC, C2, TBT, and FK Freeride. its annoying when you really cant tell what youd like best by reading about it, you have to actually try it. and most of the times that means buying first and hope you get the one you like, unless you can demo.
...so to make things simpler for you i say, GET BOTH!