Well, this was a bit of an experiment, which didn't work out. The plan was to try a 4K TV at a budget price, but I don't really think this is a good bet at the moment. Buying a 40" own-brand TV at Harvey Normans for <$500 seemed like a good idea, and it certainly was a nice looking TV, I couldn't fault the image. A Chromecast turned it into a smartish TV, although very Google-centric, as it requires a Google browser. I've lived without any Google device (never owned an Android phone) for a long time now, so they don't know much about me, and I haven't had to see all those ads constantly. Still, it is a small, though annoying, price to pay for the ability to cast in 4K to the big screen.
But the best thing was being able to use it as a second monitor on the PC. This was part of the plan, the idea was always to be able to see photos on the big screen while I modeled in 3D on the PC monitor. This would save a lot of to-ing and fro-ing to see detail of what I'm trying to model, as the 3D tool really requires full-screen. When I first connected the TV to the PC via HMDI, it just worked as a separate 4K screen, and tools like Lightroom, which I use to 'develop' digital photos, really take advantage of the extra screen -- there's a 'loupe' tool which I use a lot to see detail up close, and the first time I pressed the loupe button with the TV connected, it automatically put the image on the TV at full screen, edge to edge. Beautiful stuff. This really improves the speed of modeling by a good factor.
However, over the weekend the TV stopped working. I have yet to return it, but I won't be getting another the same, I'll go for my original choice, a 40" Panasonic HD, rather than 4K. It won't be the same for viewing photos full-screen, but it won't really make much of a difference for normal media viewing -- there isn't a hell of a lot 4K content out there, so I'd be happy to live without it.
So, the moral is, if it seems like a great deal, it probably isn't.