RE: thanks
The SMP, MRX3, and 950 are all good cars. I have had the opportunity to drive each (but trusted friends and I don't own any 1/8th).
If you can get parts for the SMP, it is a very good car and have many upgrades for other cars which comes stock with the SMP. To my understanding, the SMP parts will be a bit more expensive that the MRX3 and 950.
The 950 felt good with my driving style. The MRX3 (to what I saw) is easier to tune (chassis) and the parts are cheaper. If I have to get a 1/8th, I probably get the MRX3.