So, I got up early yesterday to pick up my copy from the Royal Mail Delivery Office (due to the missed delivery on Thursday).
Started actually playing at around 11am (after first installing both discs, downloading the free day 1 DLC via Cerberus etc.)... stopped at around 5:30pm. But only so I could go to ASDA & get stuff for dinner.
Had another hour on it in the evening, & then went to the pub.
Returned from the pub at 12:30am... & started playing again... until 5:30am
Absolutely love it. My GOTY for 2009 was Uncharted 2. I'm pretty certain that although it's only January, my GOTY for 2010 will be Mass Effect 2.
BioWare have somehow improved upon all the good stuff from ME1, plus have also managed to fix the admittedly crappy stuff from ME1 (e.g. combat, inventory, Mako).
Story, characters, script, voice acting, all that is top notch, as to be expected.
The graphics are much improved IMO on ME1, & gone is the awful frame rate & freezing.
The combat is so much better. In ME1, I found the combat to be a distraction, a chore, & turned the difficulty down to Casual, just so I could breeze through the tedious combat & get on with the story. In ME2, the combat is actually very good, & the cover system actually works well. OK, combat-wise it's still no Gears of War or Uncharted, but it still makes a very good attempt at being a 3rd person cover-shooter (& unlike Gears, it actually has a decent story).
No more Mako driving...
Inventory... much simpler, & much better.
Awesome stuff.
So far I have recruited The Professor & Archangel, visited the Citadel, done one N7 mission, & done some scanning. When I finally stopped last night (or this morning), I had just started "Zaeed's Revenge" (the mission you get after recruiting the DLC party member).
Re. Archangel...
Mordin is great.
The Citadel... I love all the little touches, the little references on the news & the adverts to stuff from ME1 - even minor things like the all-Elcor production of Hamlet

.