A lot of people say otherwise, but I don't find the SL-R to be all that buttery (disclaimer: I sized up for freeride though). I did a short run on my friend's Fanatic FTC a couple weeks ago... barely even had to try to butter the thing! He says it's great on rails and boxes too.
neither the sl-r or evil twin are your buttery flat land board. i have been on tons of noodles and nothing at all even comes close to the bataleon airobic. its just fun to ride and has more pop then the artifact and WWW put together. the only challenger to the ultimate flatland noodle i have yet to ride is the signal park rocker which may just take the cake from the airobic from what i hear..