They both have some problems.
In enV series, the "hinge" where the two halves open is a significant weakness. Repeated stress can cause the hinge to break.
enV Touch is a touchscreen phone, so the entire screen is a weakness.
However, I must say that being an former enV user (enV 1, that is) that phone lasted me a while, and I was a heavy user. Didn't try the Touch at all. Went from enV1 up to Moto Droid.
---
Kasey C, PC guru since Apple II days
Don't take life too seriously; you won't get out alive.