I don't really get the hate for Sonic water levels. Yes, you have to slow down and hunt for bubbles, but the stages are far from impossible and are quite easy if you just pace yourself and stop for a bubble when you see one. I thought Labyrinth Zone was a nice change of pace, and I loved the environment. Tidal Tempest is one of my favorite stages in Sonic CD, due to the clever little switches and use of water in the level. Hyrocity Zone (NOT Hydro City zone as screwattack incorrectly call it) was a fun water level, much more speedy sections and I found that a skilled player can avoid much of the water if they don't fall into it so much. Plus, you have the damn bubble shield! Get one, don't get hurt and you're set. Lost Labyrinth in Sonic 4 was one of my favorite Zones, and the underwater act is a cake walk.
In the 3D games, Aquarium Park has really been the only underwater Sonic stage (Aquatic Mine is Knuckles, bro!) and I loved it. Very forgiving drowning deaths due to the infinite jump and the drill wisp power allowed for speedy movement.
And yeah, the Ecco hate needs to stop on screwattack. Booting up Ecco late at night with an adult beverage is a real experience. The SEGA CD sounds so sexy at night.