Both great players in the same ballpark but I'd take Stamkos. I'm sick of hearing the "Stamkos won't do squat without St. Louis" gibberish. The kid returned from months off with a broken leg and is still performing at a high pace while the almighty St. Louis got dealt to the Apple and has been outperformed by Benoit Pouliot for crying out loud. Stamkos will be 90-100 points worth of fine and when he clicks with Jonathan Drouin, watch out. This is no knock on Tavares, however, as this is close. The way I see it:
Stamkos = a steady dose of 94-100 points per with 108 potential once he starts clicking with Drouin.
Tavares = a reliable 86-95 points a season with 103 potential in the perfect year if/when the Isles could lure some quality talent.
As for the 120 stuff for Tavares, Dobber is a bit too generous with his guys once again IMO. A healthy Sid was only able to bag 102 this year in 78 GP - there's no way JT touches 120... not gonna happen folks. Those insane 150 point "upside" numbers for players like Malkin, etc. only look good in the Guide but they will never happen. My realistic expectations for the heavies:
(IF healthy)
Crosby = 100-128
Malkin = 94-115
Stamkos = 94-108
Tavares = 86-103
Ovechkin = 78-100
... followed by the Kanes, Girouxs, Getzlafs, Backstroms, Perrys, Neals, Halls, etc.