Hi Gav, presuming both cars are mechanically sound your in for some huge differences, but it's really a matter of personal preferences as to whether they are pro's or cons. i owned a Vauxhall Cavalier V6 Auto for 14 years before buying my 57 plate VXR8 Auto back in May 2011 and I loved everything about the VXR8. My fastest previous was a Sierra Sapphire RS Cosworth running 435bhp which is a bit smaller and lighter than the VXR8 so the VXR8 didn't feel hugely quick, but its the torque and the ease with which the engine does everything and the fact that there is almost unlimited tuning potential if your wallet is big enough. First thing to do is fit a Catback exhaust, its almost criminal not to have that big V8 sound. Most impressive first thing driving the VXR8 is the incredible brakes, then the endless torque which makes just about every driving situation effortless. Then there was the effortless country lane overtakinhg. Your Astra is, I imagine, all top end and gear changes to get it going fast plus you've got the front wheel drive torque steer? All gone, the VXR8 is effortless by comparison. First time you go into town you will realise its a bloody big car and parking takes a little preplanning and practice. And the looks you'll get even above what you used to get in the Astra and the M3 For me the biggest factor though is the huge grin I get every time I take it out for a drive, even 3 years later, sometimes I go out just because i can. Of course i want more, more noise from the exhaust (Monkfish performance pac) and a Supercharger for the whine and extra power and when wallet permits Go get a test drive and let the magic wash over you!