I can relate. I almost quit the game in the sewers myself. There's a few more areas that evoke the same feeling(combat that just goes on and on and on) but I think they are slightly shorter. Not 100% sure though, I got bored easier when my character was a good enough fighter to breeze through everything.
All in all it's a typical troika game. Interesting in many ways but you have to be willing to overlook a lot of serious problems.
BTW Linoleum - thanks for pointing that out! Worked like a charm :)