Just a couple interesting notes comparing Letang if you care about advanced stats
(first to Zubov and Chelios)
At the end of this season, Letang will probably be ahead of Zubov in point shares through 13 seasons for each if not almost exactly even with him with more than 100 fewer GP's.
A weird stat is (points shares/games played) which Letang and Chelios are almost exactly the same through their first 13 seasons.
(now comparing him with some modern counterparts)
Letang leads Chara, Keith, and Doughty in my made-up (point shares/games played) stat - which would just mean he produces more point shares in the average game he plays.
Letang is also 3rd in the entire NHL in expected +/- (behind only #1 Crosby and #2 Bergeron) - and is the #1 Dman for expected +/- since they started keeping the stat in 14-15 on hockeyreference.
You can quibble about the usefulness of things like point shares and expected +/- but it's clear that Letang is absolutely no slouch but is very rarely recognized for being as good as he is because he's a hot head, he's got an injury history, and he plays on a team that has Sidney Crosby and Mr. 101 Malkin.
I'm not saying he's better than Zubov, Chara, Keith, Doughty, etc. because of point shares and stuff like that - but I do think as a caliber of player he 100% belongs in that class.