Aww, I just bought this at £48. tried to cancel to order again but 'it wasn't possible to cancel' despite not shipping yet.
I got the MX one for the missus as tge BX don't go big enough... At least not where I bought from
Only major difference between MX and BX is power loss protection and write endurance rating. Both drives saturate sata port and crucial slightly tweak firmware to give MX a slight speed advantage.
I used Minitool Partition Wizard which was pretty fuss free. Cloned the disc and swapped them over. It's a shame I had to faff with downloading and installing the Acronis tool but all good in the end. Totally transformed a couple of old Lenovo X230's. Happy boy and wife and a happy wallet for me (y)
If you haven't tried it already I think macrium reflect does a good job and I've had no issues with it in the past :)