I bought it for the Pro-800 and it fits to perfection.
The case feels really great quality and there is a space behind the synth to put all the cables and PSU connected, so you can definitively play the Pro-800 directly inside the case, which is what I do and I love it.
The case has little feet both in the vertical and horizontal direction, which is very convenient, but the feet are hard plastic and not grippy at all, so the case slips when you put it horizontally on a table to play the synth which is the only downside of the case.
The plastic feet aren't easily replaceable either, so you can't switch them for rubber ones, since you would need to remove the interior lining for that and that would destroy the case.
I'm planning on covering the case's plastic feet with cheap hollow rubber feet replacements on sale here.
I'll update the review when I do it.