Frankly, you have a very good system as it stands.
While there are a few small tweaks you might want to do here I would stand pat with the logic board you currently have. I would switch your drives around putting the HD back in the HD bay. The HD SATA port has crash guard protection which you don't have within the optical drive SATA connection. Sadly, you are facing a SATA issue within the optical drives SATA connection. Unlike the HD SATA port which runs at SATA III (6.0 Gb/s) the optical drive port is only able to support SATA II (3.0 Gb/s) drives. Here's a reference: OWC Data Doubler review the note in Red at the bottom. It makes no difference who's carrier you use the issue is within the logic boards SATA services.
OK so what to do here?
You'll need to find a Fixed SATA II SSD to use in the optical drives SATA port. Or, which is what I would do here is forget about the HD and just use a larger SSD (1 TG, 2 TB or even a 4 TB SSD) in its place (single drive setup). We gave up trying to use dual drives in this series of MacBook Pro's.
The other option if you really want a dual drive setup is to upgrade the logic board but by the time you add things up it would be cheaper just going with a large SSD drive alone!
What does upgrading the logic board buy me?
From a CPU performance direction the differences here from what you have and the best '12 system is only .5 of a GHz which in its self is not that much. Heres the Geek benchmarks:
MacBook Pro 15" 2.2 GHz i7" (Early-2011)
- Geekbench 2 (32): 9991 Geekbench 2 (64): 10823
- Geekbench 3 (32): 2439 Geekbench 3 (32): 8645
- Geekbench 3 (64): 2728 Geekbench 3 (64): 9768
MacBook Pro 15" 2.7 GHz i7" (Mid-2012)
- Geekbench 2 (32): 12367 Geekbench 2 (64): 13477
- Geekbench 3 (32): 3048 Geekbench 3 (32): 11760
- Geekbench 3 (64): 3350 Geekbench 3 (64): 13136
- Geekbench 2 (32): 2376 Geekbench 2 (64): 2654
- Geekbench 3 (32): 609 Geekbench 3 (32): 3115
- Geekbench 3 (64): 622 Geekbench 3 (64): 3368
Multithreaded apps will do better here than single threaded. If you are running intensive applications like CAD or picture/video editing then I could see you might want the getter CPU. But thats if you are doing a lot of intense processing.
The bigger difference is the RAM speed supported 1333 MHz PC3-10600 Vs the faster 1600 MHz PC3-12800. So you'll need to replace your RAM modules to the faster units. Here is were the performance will show up. I find faster RAM trumps faster CPU's when the CPU's are so much alike.
If you're into games then the faster dual graphics might be helpful: Intel HD Graphics 3000 Radeon HD 6770M Vs the faster Intel HD Graphics 4000 GeForce GT 650M. But then again, not that much faster and this series has a known stability issue so I think its best to stick with the older logic board.
So that leaves the display going to a Hi Res version the cost of switching out the display is not cheap and your current GPU won't drive it any better.
So there you have it! Holding pat is what I would do and just go back to a single drive config (SSD). I might up the RAM but that is dependent on what you are doing.
If you really want a 2012 model because you can justify it or really wanted the Hi Res display I would just get a used one as it would be cheaper than trying to make yours into one, even it you need to tweak it a bit (adding RAM or upping the drive).