Sorry for the long post. Hoping someone will find it useful when my saga is resolved.
2011 17" MBP had graphics problems from day one: display would severely distort when launching Netflix.com, Google Talk, Skype. For over a year, I thought it was a Silverlight or GoogleTalk incompatibility, so I just didn't/couldn't use apps or services using those plugins… for over a year. Down to 2 years of AppleCare.
I finally resolved to research and fix the problem, because I needed Google Talk for work. I eventually learned about the 2011 MBP display problems. For me, display distortion occurred when the MBP switched to High Performance Graphics mode. It was easy to confirm the problem because of the Bypass Automatic Switching setting found in System Prefs > Energy Saver. So, in addition to visiting Netflix or such, I could easily turn the problem on any time. Apple phone support concluded it was probably a hardware issue.
Service 1: Apple Store replaced the logic board and MagSafe Board. $310 flat-rate charge. (covered by AppleCare). No more distortion!
NEW issue: After a week, it began freezing for no obvious reason, and freezing during reboot.
Service 2: Apple Phone Support was unable to troubleshoot, since we couldn't even boot. Scheduled a Genius Appointment.
Since I was desperate to retrieve valuable files from the computer, I continued trying to reboot. Force shut-down. Reboot. Freeze during reboot. Repeat. I learned about Safe Boot and some other boot tricks I can't remember. I eventually got it to boot and did the things Apple support suggested. No improvement.
It takes about 40 attempts to successfully boot. Safe-booting seems to increase the chance of boot, but it's hard to know it has any affect after 40 tries. It works for minutes or hours before freezing again. Research lead me to several of possible software problems. I can't remember them. Whatever it is, it didn't exist prior to the logic board and magsafe board replacement.
Service 3: Apple Store Genius couldn't detect any problems during my appointment. I told him it finally rebooted and I reinstalled the operating system and re-upadted all software. "Genius" said, "You probably fixed it." My thought was, how often will I need to fix it? Turns out, often. Issues continue.
Service 4: Apple Store replaced the flex hard drive cable. If problems persist, they'll try replacing the hard drive. They then said the problem is the OWC third-party RAM. I removed the OWC RAM and put in the factory RAM which is brand new. I expected that to fix it. No luck.
Since then, I've only been able to use the MBP 3 times because the freeze-reboot process is time-consuming.
NEW issue: Distortion is back. Less severe and didn't last long, but was reminiscent of the original distortion I experienced.
NEW issue: During a reboot attempt, the MBP went dead and began beeping. I believe that's code for bad RAM. Since Apple said my OWC RAM was problematic (it's not) and now this, I suspect another bad logic board.
This is 120 days after the original logic board replacement. Apple repairs are only covered for 90 days.
As others have expressed, I am concerned that the defective parts are being replaced with more defective parts and I'll eventually find my AppleCare expired, 90-days out, and have never had a fully functional MBP. This actually happened to me with my 2005 Mac G5. They never completely fixed it during 3 years of AppleCare. The Late 2005 G5 was another notoriously bad machine.
Service 5: TBD
I've been nursing ongoing MBP problems for 21 months. Down to 1 year of AppleCare.
Sounds silly, but it's 200 miles of driving for each service. And they won't ship it back to me--they require in-store pickup. I don't have the time or gas money to drive to Apple every week. I've cancelled multiple Genius appointments simply from running out of time in a day. If I lived closer, I'd be in there every day until it was fixed.
I'll try to remember to post updates.