Casually playing BG2 since a couple weeks, personally. Had totally forgotten how much of a linear dungeon crawl it becomes from chapter four onwards most of the time. I still like the first game better, even though the second has better quest design (and naturally due to the level caps, a tad more complex combat).
BG1 feels like a world to explore, whereas BG2 is more like a heavily guided D&D theme park tour. ToB I never rated much at all, except for the ending.
I feel exactly the same way. I love how open BG1 feels. There are several maps that you never really have any incentive to explore aside from your own curiosity, and I find something very compelling about that. In BG2 you are told to go to X and then X appears on your world map and you fast travel there. In BG1 you need to travel all of the maps in between where you are and X, so there is a sense of exploration about your journeys.
Of course, the way BioWare did BG1 is quite cost ineffective, so it makes sense that they changed their design philosophy. Still, I very much prefer these aspects of BG1.
