(Psi)SeveredHead
Adventurer
S'mon said:3.0 giants seem about right for their CR IME - commoner stat array, poor Will saves & such. A classed giant with elite array or similar will likely be much tougher though - I had a 2nd level troll barbarian who did over 150 dmg recently in 2 rounds to a 13th level PC dwarf Paladin with a low AC.
IMO they weren't that balanced in 3.0. Not that they were necessarily overpowered or underpowered, but the high offense/low defense made them very annoying and swingy threats. Obviously anything can be a swingy threat, depending on tactics, but giants really only had two good tactics:
1) Stealth. (Usually this is a "yeah right!")
2) Ranged... need magical support to see the evil wizards. (Ready actions against clerics, and move around to reduce the cleric's cover!)