VentilatorOfDoom wrote: In fact it was way better this way. Undispellable high AC + concealment , that also doesn't require to use any spells at all to get it, unlike Stoneskin that you would have to cast on all Chars in combat,
There's your first problem- you don't need to cast Stoneskin on all chars, only low HP chars.
Especially in the truly difficult fights... Stoneskin gives you 15 DR, so you suffer only 20 dmg instead of 35? Meh. That just doesn't cut it. Having 35 AC on your Wizard (39 with Foresight, 40 with haste) otoh plus displacement to boot, without having to cast any buffs when combat starts (except haste & foresight for the most difficult encounters) but instead start offensive actions immediately - that is a difference. You won't be hit 95% of the time. Maybe you should try it.
One problem with this- eventually, your opponent will roll 20 (or, if they're using a sword, 19). And then, you're screwed. Before I was casting Stoneskin religiously, one crit was usually enough to one-shot my Wizard, especially in the mid-game. When you're outnumbered, and everyone is gunning for your Wizard, you can count on him getting critted. Those 15 damage is a 50% improvement against the most powerful of hits, and against more common threats, it actually does you better. There's a reason why every PnP Wizard or Sorceror takes it as soon as they can get it.
As for the resistance cloaks - you still can use them for specific encounters, but odds are there is no need to.
No need to? Tell me, how do you plan on beating the Lich in the Vancia dungeon without? Mass hold person on the surprise round frequently equals TPK without them (and, I know I've said it before, but that battle is a good example of why prebuffing is a vital part of D&D- high level surprise rounds are stupidly devastating without it).