I think we're very even. I wouldn't say either team is the favourite.
Hearts' best chance will be the exploit Sturm's lack of width.
Hearts' preparation hasn't been perfect either. Only 4 matches so far, with 1 more tomorrow night which won't feature many players that will start in Graz. I know Braga and Findlay haven't trained much either, and Braga potentially not being ready would be huge for Sturm.
My predicted Hearts team:
Schwolow
Altena - Fagan-Walcott - McCart - Milne
Magnusson - Renald
Miller - Guendouz - Kyziridis
Kabore
The other guy (not in this video) in the Perth to Paisley podcast is a good friend of mine, and I love The Other Bundesliga, so I definitely recommend it. It's a good preview, worth watching.