Tomb of Horrors seems pretty much like the gold medal standard by which hard-core adventure modules are judged. It's actually the third module ever written (or fourth, or fifth, depending on what 'officially' counts as a mod), and it's a test of how high the challenge level can go. So, for that, it's a success.
Whitey's uber-est PC ever, Maedth the ranger, got poisoned, fried, and evaporated into a gem. It was still a blast, for the whole group. There are things in there, that
look like coin-toss situations, but there are ways around them - divination spells, nifty items, or just lotsa summoned monsters to trip traps. That's the ethos. If a high-level party
doesn't use every resource they've got, and use them
wisely, they eat it. Eat a bucket full of it.
Henry says:
if some lich wanted to be sure you never found his remains, he WOULD probably design a place like this - no answers for the traps, death every turn, multiple screw-jobs faking you out all over the place, and you're not done even when you think you are.
Exactly. See, it's called the Tomb of Horrors. Because it's hard.