I think they're very close to even but I'd take Smyth simply because he's proven to be a more reliable offensive player at the NHL level. I'd love to see the two on a line together with a decent offensive centreman though, that would just be magic.
Alas, at least the Oilers got Steve Kelly back in 1995...
I've always thought that Smyth-Langkow-Doan would be a pretty damn good line.
With Smyth and Doan I'd rather have a little more pure skill in the middle. If the Oilers hadn't drafted Steve Kelly when the whole arena was chanting Doan, we might have gotten to see Smyth-Weight-Doan.
I think Smyth is the smarter player. He's more experienced and is your prototype playoff warior. Shane Doan is much, much more physical but tends to be very streaky, even though at the end of the season, he's putting up stats like usual. Doan is much more of a powerforward though. Smyth scores garbage goals and off deflections, but only has like 20 hits orso if I'm not mistaken. Not that hits determine powerforwards but the difference is significant (Doan 150+)..
A good mix of these two is Brenden Morrow, but he's not the carrier for the Stars as Smyth and Doan are to their respective teams.