Thanks!
The HiRise is a nice addition but it does have some drawbacks that I found annoying but not dealbreakers:
The Air seems a bit too light for the rubber padding to hold on to: when a cable is attached that has some pulling force on it; the MacBook gets slowly dragged towards that cable.
The hard-plastic padding underneath is not ideal: it makes it too easy for the stand to move around with minimal force applied. They should have made this out of the same padding material that they use on top of the stand.
I see, hopefully the weight shouldn't be an issue as I plan to buy one for a small synthesiser that I have to raise it up a tad, so the synth should be plenty heavy enough, Cheers.