I think the paint work is brilliant AP. The armour looks superb, the cloak (whatever you may think) is well executed and I'm a big fan of the sword as well.
Overall, the balance of the model is terrific. The colour palette is well balanced; I love the counterpoint of the red sword and Soul Stones contrasting with the cool armour and cloak tones. Just really well executed.
I am, however, unsure about the head. It may just be that I really like the Visarch head. I'm normally all for head swaps to add character to an army. In this case however, I don't think that the model screams 'Visarch, protecter of Yvraine, sword of Ynnead.' I think it just takes it a little down the road of 'Gary, Collector of Vintage Maps, Part time Barrista at Costa'...maybe I just hate that particular head. I dunno. For me, I'm just not sure it works.
But that said, it's still a terrific model and (I don't think I've seen enough of your Eldar army to make this judgement) it probably fits the aesthetic of your Eldar perfectly.