My wife has one. Here is an ad hoc review!

Upsides:

1. Yay, it's 2007 finally, and we have more than 2560x1600 in a desktop display!

2. Jokes aside, 3840x2160 is fairly breathtaking. It is quite choice. If you have the means...

3. Only $700. Sure, that's still not as low as a 3840x2160 display would be today had the living room television not converged with the desktop computer monitor, infecting our workspace with the taint of HD. But it's not $4,000, so that's something to celebrate. And, lo, it's cheaper than a name-brand 30" display. It makes me want to shake Dell, HP, and Samsung fiercely until they admit they've been price-fixing 30" because desktop-be-damned.

4. It's sufficiently large to be nearly immersive, which is something I really want for my desktop environment. I want to be able to completely fill my field of view with very high-density pixels. VR goggles need not apply, yet.

5. It's fairly lightweight and thin. Something bothersome about desktop monitors is that, unlike televisions, they are manufactured with serious heft. Nothing about an LCD should require a four-inch cabinet depth, but there it is in every one of my U3011s. For shame, Dell. The Chinese have shown you up. Of course all laptop displays since the early 2000s have done the same.

6. The bezel is fairly trim at about 1.5cm. Trimmer than my U3011s.

7. While it's glossy, it's not offensively glossy like some consumer monitors.

8. 3840x2160 for $700. Why not, right? Right. RIGHT.

Downsides:

1. It's a television. It's got speakers. Yeah, no kidding. And a remote control! Very well, I'll just stow that in a drawer somewhere. But more onerous than these features I'll never use are the "features" that are not features at all, such as a 5 second SEIKI splash screen when you turn on the monitor. No, monitor, don't do that to me. Just wake up and let's get to business. Oh, I forgot, you're a television. That also explains why you just turn off when you lose the signal on the HDMI connector, not to re-awaken when the HDMI warms up again.

2. It's a Seiki. Yes, they deserve huge amounts of credit for kicking the collective ass of the incumbent manufacturers. Thank you Seiki! But also, it means it's not exactly the finest engineering around. The backlighting is uneven and the materials are second-rate. The back is utilitarian. Incumbent manufacturers at least fashion some fairly nice looking plastic bits and bobs on the back side of monitors. But so be it. I'm not buying the monitor as a piece of furniture.

3. The power buttons are very crunchy/clicky hard buttons on the back side. Since you have to click one of those every time you sit down (due to HDMI not awakening the monitor), I worry that eventually the button will break.

4. Most importantly, it's HDMI 1.4 and not HDMI 2.0. This means at the showcase 3840x2160 resolution, you're going to get 30Hz—30 frames per second. This causes a notably sluggish feeling to animation and mouse control. It's serviceable for getting work done and consumption of Facetube content. My wife doesn't play games, so she is tolerating it. If Seiki drops HDMI 2.0 into a next-generation of this monitor, I'm grabbing one.

5. Yeah, it's 39". I'd prefer to see this resolution at something closer to 30", thereby increasing pixel density. Better still, I'd like a 50" display that cranks something closer to 8,000 by 5,000. I can dream, no?

6. Windows 8.1 is NOT (I cannot emphasize this enough) engineered to work with high-density large form-factor desktop displays. Metro apps are a joke on my 30" displays and they're a tragedy on my wife's monitor. Metro Skype at 39" is ... I am at a loss for words ... you have to see it to believe how idiotic it is. Further ranting at [1]. Similarly, it's not touch-enabled.

7. It's glossy. Matte for life!

[1] http://tiamat.tsotech.com/microsoft