Welcome to the site!!
We are glad to see your looking at the IS-F!
It really is a great car? Have you driven one yet? Been to the dealership to look? They are amazing cars (as I'm sure you've read on here before). Reliability hasn't been an issue at all (knock on wood) There haven't been random CEL's or anything of the sort I've heard of from anyone with the F (nor have I had any myself). Toyota's are extremely reliable cars and I wouldn't worry to much about their reliability.
As for the difference between the 08 and 09, check out the link below
http://www.lexusf.com/forums/showthread.php?t=649&highlight=2009
We are glad to see your looking at the IS-F!
As for the difference between the 08 and 09, check out the link below
http://www.lexusf.com/forums/showthread.php?t=649&highlight=2009