I've been doing nitro 1/10 trucks for some time now and it really comes down to how good you are at tuning the engine and keeping it healthy. With keeping engines running you have to worry about break in, compression, fuel, mixture settings, fuel lines, engine temps, glow plugs, air filter, and some other things. If one of those things isn't working, engine isn't going to work or work as well as it should. With electrics you have the entire battery/esc/motor setup then off the car you have expensive charging equipment. Electrics get more complicated when you want longer run times by running LiPo's, want to keep you Ni-type packs healthy by cycling them, or want super speeds of the brushless motors. I have no doubt that electrics can be just as expensive or complicated as nitros. All in all I think if you have a good setup and battery recharger/conditioner electrics are easier to run reliably.