The only cave I hate is RSE Victory Road. It wasn't exacly hard, and the encounters don't bother me one bit since even when I was younger I used repels. The biggest problem I have with it (besides one of the trainers being a double battle with a Slaking and a Gardevoir, and the Gardevoir uses ability switch [making Slaking virtually unstoppable~)] is that you need almost every HM in-game (everything but Cut, Fly and Dive) to get through it. That made it so that I had to take TWO HM Slaves, also letting the two most overleveled in my team in the box, and making them severely under leveled after I was done with the cave. The annoyance may also come from the fact I only learned you needed waterfall, rock smash, and flash (I knew you needed strength, like in all VRs, but that was all) mid-way through it, making me go through all of it four times.
Part of it may also be from the fact that the pokés you can catch there were 2 levels under mine, making 2HKOs and 3HKOs very common. Which made me feel weak x)
I actually love Icy Path, and even though Rock Tunnel was a pain before I decided to bring flash slaves (I was 6 the first two times I went through it), I've grown attached to it. I like puzzles (poké ones, mind you, most of the others are plain boring) and sliding around pushing boulders in ice is fun, imo.