I guess you are ranting in the wrong forum.
IWD2 is actually the IE game with least impossible final battle. In my game I won it at the first attempt although my party was already very low on spells from the battles before, the last rest was 2 epic and several small battles before, I didn't know you could rest just before the final battle.
The IWD (normal, HoW, TotL) final battles were harder but they didn't require too many attempts or cheese either.
I didn't have a problem with the PST final either.
The BG,TotSC,BG2 and ToB finals are unfair on the other hand, but those games are unfair anyway, you often get into situations where you are supposed to reload and use preknowledge or other cheese. I think it's considered by the developers as feature to double (or quadruple) your overall playing time. (Your "fun" at those final battles lasts at least 10 times as long.
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