Everyone hold your goddamn horses.
I disagree that Floyd's instrumental ability is lackluster. Roger Waters is the least talented of the bunch, I'll agree with that; but as was said, his songwriting capabilities make up for that. Gilmour may not be the most technical guitar player, but he's conceived of some of the best guitar solos in music history, and his playing is far more tasteful than most guitarists (I'll take Gilmour over Page any day). Now, you have Nick Mason (drums) and Rick Wright (keys), who are two of the most talented instrumentalists in the business. Mason is a fucking powerhouse on drums (as illustrated on the
Live in Pompeii set and other live shows) and Wright is a classically trained pianist; he can play classical, jazz, rock, you name it. He was, by far, the most talented member of that group, and his instrumental ability rivals most professional classical musicians.
Their early material is clearly inferior to their later material, but once you get to
Meddle the entire catalogue just takes a massive leap. That's their golden age. Once you've learned to appreciate those records, then move to their early work, within which you will also come to find several little gems and truly astounding moments strewn throughout.
Pink Floyd is definitely not overrated. I've said before: it's fine if you don't like them, but no way in hell are they overrated.
EDIT: also, Grant, which vocals by Waters do you think sound uninspired? I find him to be one of the most interesting and emotional vocalists in the history of rock music. David Gilmour's vocals can often sound very lethargic, but I think that offers a nice contrast between the two singers (see the song "Not Now John" on the album
The Final Cut; both vocalists take turns singing, and it creates a nice dual-personality effect). Gilmour sings the verses; Waters sings the pre-chorus and the softer, subdued parts, and the final verse.
EDIT 2: I totally thought this was the non-metal music thread.