Martin's right!
I do have the remastered m300strings on my m400 and they sound stunning if you stick them into a pool of reverb. Lovey lovely sound, and the "remaster" which I know some people think "unthinkable" doesn't detract from the sound in any way. In my opinion it enhances it because you can play in many more keys, because the originals are only playable in but a few.
AndyK