Yeah, those level designs in the first Halo were a drag. I suppose what bothered me most about what little I saw of the second one was what I felt was repetitive game-play. Just clearing one room after another is the kind of mindless shooter that does very little for me. Maybe I've been spoilt by Valve who are masters of pacing and seamlessly weaving narrative into the world that anything else tends to feel a little shallow. More than anything though, Halo just feels like it lacks any real personality and the world just has a certain "safe" bland vanilla feel to it.
I wouldn't call myself a PC purist or anything, just lacking in funds so sticking with a platform I already own just makes sense and the savings are generally worth missing out on the odd console exclusive title. By and large, a lot of the really good games come out on PC still and the prices tend to drop a lot more and indeed, more rapidly too than console titles.