It seems like you have interest in a lot of cars.
I would say go test then all and see for yourself which you like best.
As for the CLS, you won't be getting one in the $50k range unless high miles. Best advise is to avoid high miles Mercedes at all cost.
2011 535i Alpine White, Oyster on black interior, Premium 1 & 2 Package, Magnaflow Full Cat-Back Exhaust, JB4 Stage 2