I can read pretty to very fluently on upright bass and I can get by reading on the bass guitar, although I'm going to work on that. I started out playing classical double bass in school, so it came along with that. I can read treble clef painfully, and tenor slightly better.
The way I see it, there's no disadvantage to being able to read, and it makes analysing and understanding music much easier, as well as giving you the ability to jump straight into gigs; for instance I depped (badly) in a musical for one night, but I got by sightreading it and following the cello player.
Tab is next to useless in ASCII format, and only worthwhile for fingering difficult things when accompanied by notation. The fact that it doesn't show rhythm hamstrings it IMO.