I pre-ordered the Razer Blade Pro 2016 GTX 1080 version and just received it.
I feel pretty qualified to review this because I actually have 2x 4k laptops 17.3", 1x 4k 15.6", 1x 17.3" 1080p. All with the same CPU.

Obviously, the idea was to use this for multiboxing.

First off, the price is pretty insane, it was about $4k with tax.
Here's a link to all the details: http://www.razerzone.com/gaming-systems/razer-blade-pro

It's has a 17.3" touch screen laptop with 4k resolution.
It has a GTX 1080 with 8 gigs ram.
32 gigs memory
512 gigs SSD storage - Raid 0. It's using PCIe 4x lanes as well (the samsung 950 chips), so you get insane SSD speed, like 20Gbs.
MECHANICAL chic-let keyboard - best keyboard I've ever used on a laptop, you hear the click click

The laptop is less than 1" thick, but only shaves off about .5" width and length from the alienware 17.3" laptop. I thought it would be a bit smaller.

So I installed WoW and took my 5x level 110 druids out for a spin. WoW loaded REALLY fast, about 2x faster than my Raid 0 desktop setup.

Gameplay was 60fps, smooth as silk at about 5 graphics level.

The mechanical RGB illuminated keyboard is really nice - not as nice as a real keyboard, but it feels much better than a standard laptop, but there is a trackpad in place on the number pad - so if you use the number pad - you're out of luck.

Speakers were decent, just don't turn it all the way up or you can hear a bit of rattle. I almost always use headphones, but in this case I just played with speakers on.

Multiboxing a full dungeon did make the laptop pretty loud - with fans blowing. Not sure how you'd get around that. The laptop did get warm, but not so warm that it was uncomfortable to play.

But - after all was said and done - this was the first time I multiboxed on a laptop where it felt as good as my desktop. The only thing I missed was a massive screen.

Overall, the 4k screen was perfect/beautiful. Performance was perfect with 5x max level characters. 60fps all the way. No slowdowns at all that I noticed, seemed almost exactly the same as playing on my desktop, aside from the massive monitor. And the fact I could lay in bed and play and got some quests done before reset that I wouldn't have normally. (Not sure that alone was worth $4k though)

So, if you have money to burn, you might want to check it out when it's available for pre-order again.

However, you also might want to check out other 4k laptops with the GTX 1080 for a more cost-effective price - that card is a beast.

On my other 4k 17.3" laptop (gtx 980m), it seemed to make more sense to use 1080p resolution, but with the GTX 1080, 4k makes an insane difference when boxing 5 characters. You can actually see what's going on, even on a 17.3" screen.

-Kick