How much do they want for a flywheel? That would drive my decision vs. how much I'm already spending on the repair... For a 2009 car I'd probably just be replacing it if it was myself.
Is it warped at all (i.e. measuring it with a dial indicator on a lathe or similar)?
If you can't tell... Find out or replace it.
If it's not warped you can probably just rough it up with some sand paper to seat the new clutch.
Current: 2012 X5 xDrive50i, 2012 Z4 sDrive35is
Previous: 2011 X5 xDrive35d, 2008 M5, 2006 M Roadster, 2005 645Ci Convertible, 2002 X5 3.0i Sport