I own an E-MAXX and a Traxxas Stampede. I have done some major work on my Stampede, but my E-MAXX has only required a few cleanings in the two years I have owned it. It only needs a cleaning after a run in the sand or loose dirt to get the grime out of the bearings. I personally love my E-MAXX. I have not had any broken drive shafts or gears in two years. That does not mean I dont run my E-MAXX pretty hard. I have broken the front skid plate and the front bumper mounts. I have a set of matched 2400 V-MAXX batteries from team orion that give me 18-22 minutes run time. I have also paced my truck against a T-MAXX and a Sport MAXX. On a good battery charge I can hold my own against the T-MAXX and the Sport MAXX only gains slightly in a 60 ft. drag race. I like electric because of the clean factor. My budies T-MAXX looks nasty and just picking it up with leave grease and oil marks anywhere it touches you. Yes you will loose some power as the batteries die down, but that can be moderated with a good set of batteries. My V-MAXX batteries give me 15 min of full power and only a short 3-7 min die off.
Another thing about elec. vs nitro is the torque. Electric motors will always have more torque then a gas engine. That is why locomotives use a Diesel power plant to produce electric power for the real drive motors which are electric. My E-MAXX can pull a steeper hill then the T-MAXX because of the torque.
All in all preferance is the real factor. Nitro will give you horsepower and full power untill the tank is empty, then all you have to do is fill of the tank and off you go. However, you have to keep you engine tuned and go through the breakin process, and if anything ever goes wrong with your engine it can be a pain to get it repaired and retuned properly. Electric is clean and has massive torque compared to Nitro. Downside is you will loose power as you loose charge in your batteries, and changing two batteries takes some time to do. Also unless you have 5 sets of batteries, your total run time is shorter then Nitro.
I know this is a long post but I wanted to give as much info as I could about the truck I have the most EXP with, the E-MAXX. I love mine. I dont know of any other electric 4WD truck that even compares to the E-MAXX. The only thing better would be to go Nitro and deal with the engine tuning.