They all come from the same Chinese factories.
The Seiki TV is very good quality. Its downfall: only has HDMI 1.4 ports, making it utterly worthless (just like all other 4K TVs currently on the market)
Only DisplayPort and Dual Link DVI have enough bandwidth to handle 4K @ 60 Hz... but of course all the 4K TV manufacturers so far are complete morons who refuse to put a single DisplayPort input on their fancy new TV that costs thousands of dollars... instead restricting us all to the pathetic HDMI 1.4 standard which can only do 4K @ 30 Hz. Completely unacceptable for stuff like PC gaming, which of course is the biggest source of 4K content right now and should be for the years to come... all 4K TVs are worthless until they include input methods that can do 4K higher than 30 Hz.
The irritating thing about this insistence by the TV manufacturers on locking us all into the HDMI standard... is that it would cost them basically nothing to also include a DisplayPort on their TVs... DisplayPort is a royalty-free, open standard, whereas HDMI is proprietary and requires a license fee for every HDMI port included on a display. It looks like they are going to force us to wait until HDMI 2.0 until we get a proper 4K TV... which means either fall of this year, or more likely, 2014.
I can't wait to get into PC gaming @ 4K, and I would have jumped on that Seiki TV if it had a DisplayPort, but because of this stupid design, I refuse, and they have lost a sale. That thing has a VGA and a composite input, FFS. Who are these early adopters jumping on 4K TVs to hook up a composite video device to them?! DITCH the composite and VGA inputs and put a proper input like DisplayPort that can actually take advantage of your TV!