This sounds an awful like my first experience with the Throne of Bhaal. I played through BG and stormed through the magnificent BG2, slaying dragons and liches, but stopped playing the Throne of Bhaal at the Fire Giant cave. There are soooo many Fire Giants! I was pretty burnt out so I played through something completely different, Saints Row 2
, and picked up Throne of Bhaal later on.
In the very beginning the combat encounters are offer little but brutish "hord-like" mechanics of high level enemies but after you deal with the Fire Giant leader, the game opens up into some of the best boss battles I've ever experienced in any game. They combat encounters are truly incredible and surprising. On the higher difficulty they will require creative tactics, clever knowledge of game mechanics, and a bit of the old luck
Watchers Keep is also an incredible addition to the game, an excellent dungeon of puzzles and difficult battles.
I would defiantly agree with Bloth, its far more of an ARPG, but its some of the most fun combat I've seen in any game. Its like a terrific sandwhich, but with a hair on it (the Fire Giants), but of course after you pick off the hair the terrific sandwich is still there
Use your buffs religiously, Haste and Improved Haste will help significantly, Clerics are badass (dwarf Cleric Power!). Spells such as Sanctuary are great for pulling back and using spells such as the AoE heal....err.....I can't think of its name at the moment but I am sure you know, and
always remember enemies will also buff religiously so make sure to pack your debuffs. When bosses begin using spells that protect against enchanted weapons and huge dragons are eating you with improved Haste
Pack. Your. Debuffs. Pack them :yes