OK, I've finished my update of my mid-2013 MacBook Air (MBA 6,2). I had a stock 256GB SSD (Samsung) and I'm replacing it with a 480GB Corsair MP510.
Installation was easy (but don't forget to plug the battery back in before putting the bottom case back on), but I did some things on the restore side that wasted time.
The method I used for restoring my system was to install macOS High Sierra using a bootable USB Install drive. I made a Time Machine backup on an external HDD right before I started the process. The plan was to install macOS onto the new SSD and restore from the Time Machine.
This is where I had some inefficiencies.
My original SSD was formatted in APFS. My Time Machine backup was formatted in MacOS (Journaled). When I installed macOS onto the new SSD, I selected APFS (case-sensitive) ... don't know why I did that, thought it might be a good idea. After the install finished, I selected restore from Time Machine and got an error. The dialog box indicated that my source was not formatted in case-sensitive while my destination was. Uggh! (NOTE - my Time Capsule backups also didn't work)
So I compounded the error at this point. I reinstalled my original SSD with the intent to make a new Time Machine back-up using APFS (case-sensitive) as the format. I wiped the Time Machine HDD and formatted it in APFS (case-sensitive) and tried making a backup. Uggh! Time Machine drives have to be formatted in macOS format. Damn, I wiped my back up for no reason.
At this point, I verified that my original SSD was in APFS format and not APFS (case-sensitive) and decided that I'll re-install macOS onto the SSD in regular APFS.
Swapped the SSD back in. Did the Install process again and was able to restore from my Time Machine backup. All of this took hours, so I left it overnight, until now. Works perfectly, but I still had to sign in to things and I'm currently re-building my Photos library. I probably should have chosen to restore from a SuperDuper! clone instead. Oh well.
So - the moral here is to take note of what your drives and back-ups are formatted in. You can find this info in Disk Utility. Select the drive in the left panel and do a Get-Info to see more detail information.
Here are the speed results. The original drive had read/write speeds of 540/711. The new drive was 1313/1367. So it's much faster. Note - I used the 2GB stress test on the original drive and both 2GB and 5GB on the new drive. Didn't seem to be a difference in test results between 2 and 5GB.
Original 256GB Samsung/Apple SSD
New Corsair MP510 - 480GB