I can't comment on the DESC210, but I can comment on the Kyosho Ultima SC...
Nice bit of kit, it handles nicely and it's basicly a sized up RB5 in terms of engineering.
However, there are some notes I want to make on the car. First of all, if you go for an Ultima SC, get an SC-R (the kit version). The SC (RTR version) has rubbish shocks: they leak like crazy and the O-rings are both hard to reach and the ring that keeps them in place will probably become unusable if you try to get them out. The RTR has self tapping screws, and more than half of it is overtightened, causing the threads to strip on disassembly of the car. I even had the motor plate threads strip upon disassembly!
Lastly, one very important note on the SC/SC-R: The rims have a different offset to most SC trucks. As a result,
the car will be wider than stated in most regulations unless you use Kyosho's SC rims!