I've played it a few times now on different servers. It's funny, but now with CTF, I see much more the resemblance between the TF2 Well to the TFC Well.
The good:
+ Engineers must be more clever in placing sentry guns
+ Open spaces and multiple accesses give the Scout a good advantage
+ Lots of hiding spots for the spy
+ Multiple sniping spots
+ Small corridors in the bases helps the Pyro
+ Distance between bases make good teleporters invaluable
The Bad:
+ The neutral building is too vast.
+ Open spaces and large distances make it hard to be an offensive Pyro or HWG.
+ The water ways are questionable. If you could still somehow sneak into the enemy base using the water ways, it would redeem it.
+ I kind of miss the trains.
I'm unsure if I prefer CP_Well or CTF_Well at this point. It's a nice alternative to 2Fort.
That's my 2 cents, anyway.