Personally, I think the TO set has excellent price/performance ratio: the parts are comparatively easy to get, and they are simply an excellent base for a necromancer (Skelemancer at least; don't know about other builds).
My Skelemancer on the previous ladder used TO. I've completed the TO set for my Skelemancer on the new ladder about 2 days ago
I'm not saying it's the absolutely best gear selection (I have never had any of the high-end uniques and runewords, but I assume you can get more with these things) --- but it certainly provides a stack of useful mods. Some of the undocumented penalities such as the chest-kicking speed are bad, others such as the run/walk are good. The look is boring, but has very limited impact on gameplay, so I don't care about that very much.
Using TO as basis, my "standard" build adds an +3 summoning amulet, a pair of +2 marrowwalks and an Arm of King Leoric (still need that one on the new ladder...). I'm the type of Skelemancer-player maxing CE and magi. On the new ladder I'm aiming to roll/buy some summon skillers...
The result is a TO-Skelemancer who is not only perfectly capable to easily solo everything (ok, maggots lair and arcane require some patience, esp. in large games...) --- in party-games of any size people usually DO appreciate having him around.
Funny thing was... I recently played my Ex-ladder TO-Skelemancer again (read above: he's TO-based, and doesn't even have skillers), and there was one guy (playing a sorc) complaining that Summoners suck. Interesting enough, I had to clear his corpse at least twice with my sucky necromancer, plus a few other corpses from "monsters ahead? Charge!"-type players. The more reasonable players, on the other hand, pretty much added to the party effort by staying around this vamp and his skellies instead of wandering off on their own and getting themselves killed.
Maybe it's just me, but I seem to have problems understanding why his sorc doesn't suck and my necro does... or, for that matter, I don't see why TO sucks. I just love it, and if I'm still playing D2 when the ladder is crushed again, I will once again make a TO based Skelemancer first.
Of course, there is at least one thing I don't like: Tal Rasha has MF in it. IK has some MF in it (I think). TO has no MF and no sockets, so with my standard setup I'm stuck with 2 ptopazes, 2 mf rings and gull on weaponswitch. IST (both for Gull and wand), Gheeds and 7% mf charms are all on my wishlist for this season, though
