From my experience... I would say slim to none.
They will not refurb the unit because you dropped it. Yes, it may have been the holsters fault but....
The standard response I get is "just send the unit back in for warrianty replacement. We will check it out". Oh yea... and if it's not covered they send you a refurb and charge you for a new unit.
I had this happen for a client. He got his replacement phone backand we thought all was well untill he got his next phone bill with the charge on it.
Why not buy a broken unit and reskin yours? Check out this ebay item. http://cgi.ebay.com/Blackberry-8700-...QQcmdZViewItem
Let us know how it goes.