I bought both the PC and 360 versions. On the PC version, planet scanning is a bit easier because you can move the scanning "tool" much faster.
I've found that on the 360 version, if you press the scanning trigger rapidly instead of holding it down, you can scan a bit faster.
I was very impressed with how different the playthroughs can be.
On the PC version, I started with a new character and used all of the default settings for the major decisions from ME1.
On the 360 version, my character was a level 39, and I had saved the council, and Wrex was alive. When visiting the Citadel, the conversations that took place were vastly different, since in one version the Council was alive, and the other version they weren't.
Also, a fun thing to do in the Citadel is to visit every retail shop on every level and ask for a discount. You can offer to record an endorsement (from the man who saved humanity) for each shop. And every time you walk by or into a shop, you'll here Shepard's recorded voice saying "I'm Shepard and this is my favorite store in the Citadel."
I haven't found out yet if there are any repercussions from endorsing every shop as my "favorite".