Personally i would say cherish what you have as you'll always want something better!
I was tempted in getting an M when i was buying mine... However the even smaller boot made it totally impractical for me.
Also contemplated a 2.5si, as the power as nice as it is isnt the be all or end all if you dont track it. Ended up with the 3.0 not because of the engine but the spec it came with as standard.