Hardware.Info published a review on the LG 27UD59
A quote from the article:
Near the end of 2016 we reviewed a 4K-monitor that proved to be extremely popular, the LG 27UD58. This was not very surprising, as this 27-inch ultra-hd monitor offered an unprecedented price-performance ratio at the time. Whereas direct competitors had prices ranging from 445 pounds / 500 euros to 530 pounds / 600 euros for an ips-panel, this LG was available for well under 354 pounds / 400 euros. The successor to that monitor has been available for a while now, the 27UD59. At the time of writing we can find it for less than 265 pounds / 300 euros in our Price Comparison, which also makes this monitor rather inexpensive. Looking at other monitors in this price range you can only expect to find a tn-panel. This raises the question, are we as satisfied with the ’59 as we were with the 27UD58?LG 27UD59 Review
The phenomenon of the ultra-hd monitor is probably something you know well enough by now, which is why we will not go into great detail here. With a 27-inch resolution, the density of 8 million pixels is already high enough to make use of software scaling, but in 2018 this is not a big issue with Windows 10 and modern software. Mainly the relatively small applications - such as driver software of gaming peripherals, unfortunately - that do not always work well together, but if necessary you can still manage 100% scaling with 27-inch 4K. Especially if it is only necessary for a short while.