I think traxxas had some qc issues. I too started with the trx 2.5 in a tmaxx and loved it. Always held a tune and was very reliable. If they aren't broke in just right they can be real finicky. My brother and his buddy could never get thier 2.5 to run right but mine ripped.

Nitro can make a good first rc if you follow the manual and do your research. I was 16 when I got my tmaxx.