I do really like solaris as well, but I've only seen it the once and was very out of it. But in some ways it is more interesting, yes. It goes somewhere you are not expecting and is not really anything to do with "space" and the confrontation of the alien, or collapse of time.
Whereas 2001 to me is just the blueprint for a lot of other films. It's dealing with the same issues as, say, Alien and Terminator. And it's got that epic scale, particularly the second to last bit with HAL and just the sound and music. I love how its all largely silent, then that bit when he's falling through space and it is totally silent. Just so many good bits and they also string together so well.
And the way I approach it is as 3 different films. Cos it definitely is slow and ponderous. But it also nicely splits up into sections.
The Dawn of time sequence this time had me laughing so much. Its so overblown and as I said above, the costumes are so hokey. Close to farcical but somehow still works and definitely you get something extra with it.