Well kind of #1 Wlad prepared to fight David Haye and not Ruslan #2 Chagaev is a southpaw #3 Chagaev is undefeated and #4 David Haye really pissed Wladimir off so he might be mentally out of his game (though it's doubtful). I think Wlad is bigger, stronger, and has fought better competition but stranger things have happened.
And some clips for you to get a glimpse of Ruslan Chagaev so you can form your own opinion on him.
http://www.youtube.com/watch?v=Gg-c9hm-Q_I
http://www.youtube.com/watch?v=0fg5z9nb_wM
http://www.youtube.com/watch?v=br4vmwM8yYw
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