It's true that the critical consensus on Slowdive is that they got better as they went along but that did get me thinking... It seems to me the critical consensus is increasingly tolerant of Bad Later Albums (BLAs). There have been so many classic artists in recent years who've released albums that have been trumpeted as returns-to-form but have turned out to be utter shite.
I would not include the Scritti album in that, BTW. Big fan of that one. Actually, I like Cupid & Psyche a lot too, which some would probably count as a BLA.
Oh and I can't believe I didn't mention Sonic Youth. I absolutely love Dirty and A Thousand Leaves but it's really all about Murray Street, which is up there with Sister and Daydream Nation, IMHbCO. Seriously, don't sleep on Murray Street. Amazing stuff!