I know couple guys in texas who have Sr3s, one used to race it in NASA. They seemed very reliable, but make no mistake, the parts and maintenance are extremely expensive. A motor freshening is over 10K.
The only downer I see with a Radical is that they are SOOOO fast on a track that a DE is no longer all that fun with the traffic. An SR3 is good for a mid 1:40 at TWS, which is blistering compared to your average fast car - mid 1:50s.