I guess we will just have to wait and find out. I think Stamkos is going to turn things around in TB. They aren't that bad of a team, so I don't see how they played so horrible last season. They have a potent scoring line with Vinny, St. Louis and previously Richards, but now Stamkos. I just think they messed up in letting Khabibulin go. They need a goalie and one top flight defensman and they are in business.
As for Tavares, we will have to see where he goes and see if he can affect that franchise the same way. Hopefully Boston sucks and gets him, because I am a boston fan, but with my luck they will finish 8th again and get a middle of the first round pick as usual.
Both players have the chance to be great, it really just depends where they go and what they do with their opportunities.