As far as I'm concerned up until Vanilla Sky Cameron Crowe could do no wrong. Say Anything... isn't my favourite of the bunch - IMO Almost Famous is a flat-out masterpiece - but it's still a funny, warm, infectious movie.
I enjoyed this extended edition a lot. Perhaps not all the scenes are strictly necessary (the unpleasant smoking woman who talks to Lloyd outside during the meal, for instance) but the accumulative effect of the extra scenes is definitely positive - it deepens our understanding of the characters and the world. Most of the scenes that were originally cut are serious character beats, which when added back subtly change the largely comic first half into a more serious, though never heavy coming-of-age movie. I also found the John Mahoney character slightly more sympathetic, which is no bad thing.
As others have mentioned, the deleted scenes have slightly lower video and audio quality, but it's not a big deal. My only wish would be that the AVI (the version I watched, via Mediafire) used the x264 codec rather than xvid - but then I suppose the deleted scenes would have stood out even more if the video quality was improved.
Thanks for doing this edit Neglify. It's really good stuff.