If Haye finishes Barrett by decision...will it have any impact ?

For only his second fight at Heavyweight whether by decision or KO it will be an impact, Barrett is no joke and Haye knows it. As long as he wins it should be an impact considering his future plans(Klitschko).

 

Going 12 might be good for Haye. He's had suspect stamina in the past. If he can fight 12 hard rounds with a heavyweight, it might be good for him.
If he wins in a boring fight though, it will be bad for marketability.

But, I suspect that Haye will finish Barret off before 8 rounds.

 

I think at the end you're right...although if he struggles to a decision win his plans for a HW title fight might get pushed back.

I don't think it affects the fights...but the time table.