There is one and only way for polymorphing to be good... Get a
5 Druid
13 Shifter
22 Dwarf Defender
With epic damage reduction III an undead shape. When you morph - go into the risen lord. Ok, now you have like 70 dmg reduct
No kiddin, and you cant get damaged exept if by a monk or any unblockable damage.
You can sit back and roll 20's, thanks to the hotu adition of all items morphing *with* you into your 'hide' and 'claw' or w/e of the morph, youll do about 20 dmg, but then - they cant do any. They cant even crit, your undead
If the ac from all items stacked as was meant to in the game polymorphing would be *quite* good but thats not the case.
If your playing godspire it does, so good luck to you.