I have seen the mini both in person and on the photos

blame me for them
if you ask for my comments, here you go. The freehands are excellent - very smooth, detailed and well composed. The silver NMM is very good even though a bit dark in several places (which looks as if the photo wasn't lit well in these parts), and colors for gold are pretty nice.
The NMM gold isn't my favorite though. The lines don't always look OK, and the sometimes give more amber than gold look. I would also shade it deeper and add some whiter reflections to 'sculpt' the metal better. If you want it to be metal, it must look more reflective IMHO. That's why silver looks more convincing than silver.
The choice of colors and general composition is top notch. But why the heck the armour is so boring, so dull? If you go for NMM (so the mini won't be realistic anyway) and for some saturated colors, don't mix the conventions and don't paint the armour so flat. If you go for cartoonish look, highlight the armour more. Or if you want to make it so 'flat' - add something interesting to it: chipped paint, weathering, reflections, damage, patterns.
When I got the mini in my hand I thought: why the hell did he have to rush the paintjob so much? Why did he spoil such great paintjob wih this flat armour?
Subtle hihlights work well on larger scales - or large photos. But then you have to face the consequences of having to show larger photos. OTOH on smaller minis and smaller photos contrasts work better.
BTW - the varnish didn't help the mini, too... Trying to take photos on which the 'subtle highlighting' would be visible (so pretty much light was needed) only emphasized the glossiness of the mini, and the reflections made the highlights nearly invisible...
The mini is definitely your best so far, and a great example of your skills after the previous ... Morathi, which was weaker than most of your minis.
You're a greast painter and I hope these suggestions can only help you, not discourage you
