I enjoyed the SP but I wish they had spent a little more time with it. I ran into a lot of bugs that weren't gamebreaking but annoying or required a mission restart. I had issues with the last bombing run on the jet mission, for example, where I killed the guys required but just kept circling in the jet until I finally gave up after a few minutes. Other times, all the sound would cut out except for ambient noise such as wind or rustling papers. The sound would normally come back in after a few seconds but at one point was out for up to a minute before coming back in. I ran into spoken audio tracks being replayed over and over until I reached the next checkpoint and the last guy in the last co-op mission being invisible (seen this on more than one occassion).
My other issues were with the brain-dead AI. They spent all of the processing power on graphics and left nothing to making your enemies at least somewhat smart. They were always either running directly at you or taking cover where you could still easily hit them. None of the individual battles felt unique, they all really played out the same. The QTE's were also pretty bad. I don't mind a random QTE here and there, but the ones in BF3 mostly didn't make any sense.
Regardless of all that, I still enjoyed it. The story was good and I liked the style of telling it. I enjoyed the between-mission interrogation and then essentially playing out the story as it being told to the interrogators. The graphics and sound were both phenominal throughout. The gunplay overall felt really good, too. Everything that matters the most to me is there.