To be very honest if I was running 1/8 or were to buy a 1/8 scale car I would buy nothing other than a Kyosho Evolva. That's the car I like the best.
Now of the 2 cars mentioned above I think the Serpent has alot more innovation in the design beyond the typical setup of most others on the market. Serpent has, for many years been on the forfront of R/C Innovation and even invented the original Centax Clutch system. That isn't to say no other car has innovations, but I feel personally that Serpent has a better car as far as innovation and quality are concerned. I still have a sweet spot for that Evolva, but I would drive a Serpent 960.
FYI: I have no driving experience with ANY of the 1/8 scales