Just thought I'd update to say I've received my 5x X30 Blue+'s, and the quality seems absolutely spot on. Apart from the few differences like the power cable coming from the back vs the side on the 'real' XR30, it looks a heck of a lot like a Radion.
Whilst they're not mounted over the tank yet as I'm still working on my motorized light frame, they seem to be holding settings well when power cycling and unplugging them etc - But time will tell, as to whether any issues arise.
I've gone a little overkill with 5x fixtures that'll be running perpendicular over a 5ft tank, but at least the spread should be spot on!