Liking mine a lot.
I have a new 21.5" 2.8 i7 with 12GB of RAM and a 2TB HDD. I was coming from a 5+ yr old 17" 1.83GHz Core Duo so of course my perception of the new machine is somewhat skewed. That said however I am loving my new i7. It flies with everything I've thrown at it so far, editing RAW photos using Nik software for my 5K+ pic Aperture library, 25K+ iTunes library, movie conversions with Handbrake, 10+ windows open in Safari, MS Office, etc. I have not once seen a beach ball under the heaviest of processor work.
The screen size is perfect for me as I didn't have the counter space for the 27". Noise is non-existent and the new Magic Pad is fantastic especially with Lion. Overall I give it a 10 out of 10. You won't be disappointed. Only need to decide HDD size, SSD and how much aftermarket RAM to add.
Good luck....