Realisitcally, your right. But that still doesn't make Tegal Manor any less of a great classic to those who know of it and own it. Same thing about Rappan Athuk and Tomb of Abysthor. To those of us who own them, we know how great they are. Plus Rainbow Mage and several other exceptional modules put out by Necromancer.
So to those of us who know better, Rappan Athuk is the best and deadliest of all 3E modules. There are deadlier, such as Black Ice Well (that just may have been me, I am in touch with my "adversarial" side), but RA is great and deadly.