I just finished ME3. Overall ... I must admit I really enjoyed the game.
I imported my Male Shepard who was a Paragon through ME1 & 2, and had Tali as a LI. Everything worked out pretty good untill the end. Perhaps things are different with different choices, a second playthrough .. I dont know .. but the ending was disappointing for me.
In ways, the ending I got seemed to be a good conclusion, but it also left tons of un-answered questions for me.
After it was over Im sitting there think .. "But what about.." A Fallout 3/NV type ending would have pleased me here after the main end to wrap up minor details.
My only other complaint is things seem a little too streamlined at times.
I know many are currently playing the game, or want to soon, so I will leave my opinion at that for now. To many details may ruin things.
But I can say this:
There are many complaints that the Multiplayer is a must to have all your War Assets and get a good ending. This is NOT true.
I put in around 33hrs I think it was, and had my War Assets at 100% +. Multiplayer makes it easier, as theres less to do in the SP, but you can accomplish the goal in SP if your willing to work at it.
But, from what Ive been seeing it does look as if importing your Shepard is the best route as some desicions may not have the best outcome if you do not.
But, as I mentioned, the game certainly has a few flaws. I really did not like the way the series ended either, but... ME3 as a whole was a great IMHO.
But that last 5 minutes really just wasn't up to par.
Peformance/Tech/Bugs:
Some minor things I noticed.
-Squadmates disappear at times. They might be beside you, yet you wont see them. Quicksave/Quit to main/reload fixes it. (Something do with pathing causes it I think)
-WAR Room: Sometimes the War Assests/Readiness screen shows all 0 and greyed out. You have to bring up the map, then go back for it to update.
-Character Banter sometimes just gets cut off in the middle for no reason.
-In conversations, Shepard or a Character my be invisible. (This was rare for me. I seen it 2 times in 30+ hrs of play) reload fixes it.
These do not happen often, but some minor things I noticed. Overall, the game ran very good with no crashes. Just a couple minor annoyances that pop up on occasion.
With some of the games Ive played lately, I must say this is a big +. A few bugs will happen, but nothing major or gamebreaking here.