My personal Pro's and Cons:
Pro's:
-longer runtime
-smell
-more realistic to work on
-no battery worries
Con's"
-noisy (not really a problem but if you got close neighbors, well, you know...)
-tuning can be a pain
-costly sometimes (i.e. fuel @ $25 gal, servos, motors, etc.)
-Nitro is fast, but compared to some electrics, nitro is much slower