I could never consider Pink Floyd overrated because i found them at the same time i found Led Zeppelin, and that was an amazing time in my life. I disagree that David Gilmour is not an excellent guitarist to anyone who wants to call him mediocre in any way. He is more technical than Page or Hendrix, but he is absolutely great and my favorite next to Jimmy (Page that is!)
As for the opening that Pink Floyd have only three good albums, well that is just your opinion. If that was a fact, they would have probably faded away by now. I agree that Animals and Meddle are great albums, but i also love Dark Side of the Moon (in no way "average") and as previously mentioned, definitely "timeless". I also love Wish You Were Here. I don't love all the songs from their other albums, but i do love all the songs from these "four" and they are so good that it makes Pink Floyd worthy of their long standing following. The Wall was never one of my favs...but i appreciate it for it's artistry.
and David Gilmour was a fantastic model before he became a famous musician