First game in totally unbalanced (obvious players with big latency advantage).
Next few games have been good fun. As Gzero said, lots of people creeping through bushes. Fragging them is good fun. Like I say to the kids. You can hide behind the curtains, but we can all still see your feet!
The Metro map feels overly convoluted, but that might just be the COD player in me.
Observations:
Weapon sounds are awesome (RPG whizzing past your bonce is superb).
Crouching/jumping/crawling prone are all good (You can crawl fast in prone which is really useful for getting out of a firestorm).
No sign of a server browser yet (probably because there is only one map available on the Beta).
Graphics on the console (queue drum roll) utterly overhyped. MW3 will look better without a doubt. Don't think it will play any better though. This doesn't lag half as badly as MW2/BLOPS.
Overall great fun, but the visuals are a mile away from what's been touted (IMO at least). Visually I think you're going to need the PC to do it justice.
Now if you'll excuse me, I'm off fragging in the bushes.

.
Knowing how it works is completely different to understanding how it works.
Live BQM
FTTC - Aquiss Business 45
37.7Mbps Downstream
8.45Mbps Upstream
7ms Ping