The first page post is informative however leaves specific purchase choices open-ended.
I have a mid-2015 rMBP that I got as part of a $199 battery "replacement" for my 2012 rMBP (the OG retina macbook). I suspected this machine was part of the recall that was going around for this model, but the model number was not a hit for that.
I gave it to my mom a few years ago since by this time I'd moved on to an M1 Max 64GB machine which I'm still rocking. Probably gonna drive it into the ground, it's still such a beast. The M1 Max may become a solid mobile gaming machine soon going by the looks of how well people are getting games running with GPTK2. I digress.
I came to visit my parents again now, and lo and behold the battery has puffed to high hell on the ol' MacBookPro11,5. It's 6 packs of spicy pillows, 1 out of the 6 is not as filled as the others but 5 are very very high pressure puffed up. The lid couldn't close, I mean it wasn't even close. The trackpad corners were sticking out, the entire keyboard and case was bulging. The bottom cover was quite bent from the pressure. I opened it up and ripped the battery out promptly, and now it looks like the OEM AHCI SSD is more or less kaput as well, as I'm generally unable to restore any semblance of functionality to it, keeps rebooting when logging in or trying to initiate an OS restore. So I'll need to get a new SSD in addition to battery for this machine.
Anyway that's my story that nobody needed to follow, but there it is.
From what I've seen the best choices are clearly either the Crucial P3 or the SK Hynix Gold P31. I will be choosing a 1TB SKU of either, and likely the long sintech adapter as that seems to be a popular choice. it is more expensive than the deal4go small adapter and maybe countless others. But I'll go with the sintech one.
The question is WHICH ONE TO CHOOSE? P3 or P31? The P3 is cheaper by a bit.
I am concerned that it may be difficult to install an OS with this if the drive in an adapter won't boot up internet macos recovery out of the box...