+1 on the Roli boards be a fascinating experience. Who knows, with some good old fashioned practice I'm sure one could become comfortable enough with it for use as a main gigging board. For me though, the price is seriously prohibitive. £599 for the 25 key version and that's just a controller - no internal sounds (!!) All the way up to around £2500 for the Grand. Which, by the way, isn't even "grand" technically speaking as it only has 61 keys. At least it actually produces its own noise though. Can you tell I won't be buying one?
There are some videos of virtuoso players getting incredible things out of them - Cory Henry being an example. Worth a watch!