My mid-2012 rMBP became plagued with an erratic trackpad, so I took it to the closest Apple Store and they in turn shipped it to an Apple repair center. The charge would be $310 plus sales tax. The genius at the store suspected that the trackpad would be replaced, but anything else would be included in the repair as long as there was not water damage. I picked up the repaired computer today and discovered, according to the product repair summary, that the logic board (item no. 605-3220, 2.3 GHz, 16 GB / symptom: REP MBPr 2012/2013 MLB [Multi Issue]) and the top case w/battery (605-3511 / symptom: Trackpad Cursor Not Tracking Properly) had been replaced. The computer had gotten sluggish but runs great now, which I assume is due to the logic board being replaced. That $300-plus charge seems to have gotten me practically a new computer. The genius thought the faulty logic board was the cause for the erratic trackpad, and I took it that the trackpad did not need replacing. If that is true, why was the top case with battery replaced? I'm certainly not complaining, but I was wondering what all is included with the top case.