I can tell you the durability of the Serpent Cobra is very good indeed. I haven't broken any of my cobra cars (buggy, truggy or GT) and there hasn't been any appreciable wear either. I have a buddy who has the X3 and he has broken stuff but it's still a good car. I'm very pleased with the cobra.
Serpent Viper 977e, Serpent Project 4x, Serpent 811T-TE Truggy, Serpent 811e 2.1, Serpent SRX2-MH, Serpent SRX-2 RM, Serpent SRX-4, Serpent F110-SF2, Serpent F180, Serpent 748 Natrix WC, Serpent Cobra GT 3.0, Serpent SRX8, Serpent S811 2.2, Baja 5B Flux, Atomic AMZ 1/27th, Schumacher GT12 SS.
Sanwa, Ielasi Tuned Novarossi Racing Engines, Tekin, Hobbywing, Muchmore.