I'm going to have to chime in and completely disagree with this post.
Granted, I first really got into music in STP's heyday, as I was 13 years old when Purple was the 3rd CD I ever purchased. There's an enormous nostalgia factor involved for me with STP obviously. I actually look back on the years from '92 to '96 as a golden age when alt-rock had come into it's own in the mainstream, but hadn't completely diluted. Of course there were awful bands out there, and there were some who could muster one or two good songs, but that was about it. Yet I wouldn't number STP among either of those groups.
Core: Semi-generic hard rock/alt rock. The 4 big singles that are just fun to rock out to, nothing special.
Purple: Absolutely amazing album. For latter-day mainstream alt-rock this is good stuff. Each song had a different feel and texture, some straight on rocked hard, others were acoustic ditties, some a blend of styles, they hinted at some of the sounds they'd bring to further fruition in Tiny Music...
Tiny Music...: Good for them to push their own envelope a bit and strip away the layered wall of guitars left over from Core. This record I think is more cerebrally enjoyable for the jangly looseness of it, it's more rough around the edges. Quality of songwriting had dropped though, you could tell that some songs were complete clunkers.
No. 4: They threw it all back together, sounds from each of the first three albums, but this one is angrier and punkier. Didn't fully appreciated it until recently.
Can't give a flash review of their last album as I never ended up getting it. The point of STP was not to be some respected intellectual groundbreaking group of musicians putting out niche market songs unique in style and thus more praised by the pitchfork crowd. They were a classic mainstream rock band that were able to change with each album yet retain enough of a pop sheen to please the masses. I personally like a lot more of their output than Pearl Jam's even though I will rank Ten above anything STP has mustered.