That's certainly an...
interesting helmet crest.

Can't say I'm a huge fan of the execution, as much as I like the idea (it doesn't blatantly offend my historical sensibilities, which is rather rare, so kudos on that front!). I think a smaller, round tower (think textured chess rook) would have worked better, without being any more difficult to produce.
I quite like the golden-yellow trim, though coverage seems slightly sparse in a select few areas. The placement of colors in your green is great, but the finish could be a bit smoother. A thin green glaze would help smooth those transitions. I use a layer of
GW's Thrakka Green wash applied thinly, as a glaze, as the final step in my Ork skin and I quite like the effect. It increases color intensity, slightly, and smooths all of the transitions in the highlighting, without appreciably darkening the colors (so long as you keep the application thin and avoid letting it pool).
Overall, I like the model. The yellow and green scheme is attractive and the basing complements it perfectly. The metals are also done quite nicely - the sabatons, especially, are just about perfect. It takes a model of a certain caliber to get me to pick nits, so take any criticisms as their own form of compliment. Holding this at arm's length, I doubt I'd say much more than "awesome!"