I really like what you've done with that paint scheme, it is one of my favourite (still unowned) models and it's great to see interesting takes on it. I find that when I do black glass a highlight on one corner of the glass and a pair of thin lines running diagonally from that light source corner away give the black a lot more depth and help with the glass look. For example, if you look at the crashed aquilla lander in my blog you will see what I mean.
This is exactly what I meant. It adds depth that normal varnish can't. And Iraqiel is very good at doing it the way he does