I think Hide being that bit quicker would be the first one to land a meaningful punch, fight over then IMO.
It's really anybody's fight but I might be apt to going with David Haye as I believe him to be the more skilled as well as mentally stable. But I say this with no real conviction. Herbie Hide was very fast, powerful, well conditioned and while he wasn't a master technician could still certainly box a bit.
I'd go with Haye, he is simply the better boxer. Hide is too upright, always predictably circled to his left 99% of the time and had a bad tendency to lean back to slip shots. Haye has far superior head and upper body movement making him far more elusive, which would negate Hide's slight advantage in hand speed.
I liked Hide as a fighter but he just couldn't take a punch unfortunately, as soon as Haye landed it would be over. Haye is no Hagler himself but he took a better punch. Punch resistance doesn't always tell the story but in this case it does, Hide would go down from thin air. Hide's only chance is putting Haye down early with a devastating combination (or targeting that weak toe), which I guess is possible but I would put money on Haye.