I've never seen tab with time indicated that PoppaGator describes. I wish they hadn't stopped doing that. The thing I really dislike about tab is that it doesn't seem to indicate rhythm. The best thing about sheet music is that you can pick it up and play it without ever having heard the tune. Tab without rhythm doesn't let you do that. You need a recording to go with it. A couple of times, I've seen tunes written both ways on the same page and I like that because it gives fingerings separately. When I used to play classical guitar, the fingerings were written on the sheet music and it took some wading through just because it made for a very cluttered page.

I definitely prefer sheet music over no-rhythm tab. I'm glad tab exists though because a lot of people are intimidated at the thought of learning to read music and tab provides them with at least some kind of system of notation.