That display is the heart of the P50t, and it certainly does the job. You can't tell the pixels apart, despite the larger screen and, on mains power, it's colourful and responsive. Indeed, it might be one of the most colourful screens we've seen.
Windows 8 seems to work well with it, with icons still being a reasonable size, but other programs don't automatically adjust, leaving you hunting the screen for the tiniest windows. The build is good, with the cool metal finish holding up well to pressure and twisting. The combination of a Blu-ray player and a 4K display make it a laptop for movie fans who travel, but don't expect it to go for too long before having to reach for the mains.
This laptop doesn't like running on battery power - it doesn't last long and it has a very dim screen whilst it's doing it. Compared to the MacBook Pro's eight hour battery life, 2 hours 23 minutes is extremely poor. And the screen is too glossy, which is problematic for high light environments.
While the build is good, the several plastic parts detract from its perception as a complete luxury product. That constant fan noise, whilst not loud, is an irritant. And the locations of the various ports will make it messy in use.
Finally, those benchmarks don't match its price point. The HP ZBook 17 G2 is a similar price and destroys the Toshiba in every benchmark going. The graphics chip is weak so only suited to low-spec gaming, and especially not at the 4K resolution - something just over 720p seems better suited to running games smoothly
With its short battery life and its poor screen brightness on battery, this is effectively a desktop replacement. Despite that, it's not particularly heavy, perhaps due to the use of plastic instead of metal in much of the edging.
We can't really claim to be happy with its benchmarks. Running anything intensive at the screen's native resolution is going to try this machine and we're concerned about the apparent lack of multi-threading on two of our benchmarks. These won't affect many core tasks, given the solid graphics card in support, but it does worry us about how this laptop will age.
Despite those concerns, this is a solid offering. If you're not interested in the touchscreen, then the 4K version of the Dell Precision M3800 might be a good alternative for $200 / £100 more. If you're not that bothered about the 4K and want power, then the HP ZBook 17 G2 blows the benchmarks of anything else out of the water, even if shares a similarly poor battery. And if you're after a UHD screen with a long battery life, the 15" retina MacBook Pro is expensive but reliable.