can't offer a comparison, but I looked at the two and chose the apex flight as it was slightly lighter, and not a massive significant price difference over here anyway, and then the mikron went out of stock at the shop and made the decision easy! Just took it away for a week to Malta and it was brilliant, lovely to breathe and just so light. I'd definitely recommend it.
I have heard the debate about the non standard hose fitting, meaning that if it busts you have to have a spare special apeks hose rather than just any hose, but also the argument that the hose isn't about to give out overnight anyway....