No, Duncan is just over rated, outplayed by most of his competition head-to-head. Talking bigs like Webber, Dirk and especially KG. Shaq and Kobe have the edge in most of their legendary match ups in the playoffs. Except no one wants to talk about Tim's shortcomings, oh no.
Just Kobe, Lebron and Shaq's. Specifically in that order.
Who is talking? Was he better than kobe? Zero debate yes. Shaq (there's an argument for shaq due to peak, but overall not wrong). Better than Bird? At this point I think he's made a case but you could call that overrated.
Is he a top 5-10 player? No question. If you're hearing people rank him higher than 5 then yes he's entering into the discussion. As it is I never see him over 5 so no, he's not overrated. He is for the most part still mostly underrated, and by a lot from some posters here.
I think Duncan gets overrated when people claim he was a better (not greater) player than Shaq.
Otherwise he's a top 7-10 player all-time IMO.
Duncan did pretty much everything better then Shaq. He was a much better defender, better offensive player all Shaq did was dunk and do a hook shot and Duncan did not take games off like Shaq while having no one near as good as Kobe on his team.