I picked this up on release but never got that far before dropping it for some other shiny game. It wasn't the games fault just my short gaming attention span. I've now returned to it and finally finished it. I definitely agree with most people that the first 2/3rds is excellent and the last 1/3rd is horrible. To me, its not even about bugs (though official and fan patches fixed most of those for me) it was due to the change in type of game. The good portion still took me at least 20hrs so its still worth it to play up to a certain point.
I knew some of the downfalls of the game coming in so knew to focus some on melee and I still did firearms even if it was clunky. Some of the clunky was from FPS-RPG always being a bit clunky (Issues mixing user FPS skills with the in game character stats) and from a early source engine. Once I got the shotgun firearms worked fine as secondary to my sword or sledge. I really need to play through with the less physical skills and mess with the vampire magic (I mainly used trance and suicide) but like regular RPGs I go for using swords/bows over magic.
Since I did focus on combat there were only a few reloads here and there. I didn't really have trouble until the end game where it went from fighting a few or 1 strong enemy to fight hordes of unending enemies. It went from being an RPG to being a button masher combat game. It wasn't due to bugs or a early version of the source engine. It was the game design that changed. They took the time to build those levels and place the enemies so it wasn't just a rush job. They could have just closed the story another way or used simpler end level quests instead of running the gauntlet over and over.
I really enjoyed the more modern city environment of the game. I didn't even mind the sewer level that so many hated or the first few hong kong levels but I could feel the above mentioned change in the game. I do so it as the mark where the game quality/design changes but I was expected the hordes in the sewer not a few quests out from it. So I switched to god mode to finish it off so I could at least see some of the endings.
I do plan on replaying at least the first half of the game with different characters to see how it plays out. I also want to try one of the newer fan patches as mine is very old. Not sure if I want to use the patch that adds additional content or just the one that focuses on bug squashing.