Nice How ever, I see little point when you can just use Sofarun to load disk images off a SD card on the MFRSCC+, mind you, do you include a USB stick with some nice disk images?
There are several reasons a Gotek still makes sense:
If you are a newcomer to MSX buying a flash cartridge may seem a bit daunting at first and you may not want to invest as much at the same time you buy your first MSX (which is of course a good thing).
SofaRun (or actually SofaRunIt that does the disk emulation) cannot run every game. The Gotek will run everything like a normal diskdrive would.
A USB drive with disk images can be included, free of charge.