That's my understanding. I've heard it can run a couple of transcodes as well as acting as a player. I saw it on Black Friday for $100 at Amazon I believe. Quite the deal, but it wasn't something I was fully in need of at that time. Still wish I had jumped when it was that price, because nothing is close right now.
Since I had an old computer lying around, it was a much easier call just to set that up as the server for Plex. I don't use it for any playback at all, strictly as a server.
It's kind of weird because I always viewed the HTPC as the source that needed to be controlled, and what I really like about Plex is that it just acts as a manager for my media collection, and the players are whatever I want them to be. Whether it is Shield, Roku, or just my phone or tablet. It's the fact that I have one point of control that's a reliable interface to management, and a completely different interface for my family that uses it on a regular basis and the two don't really cross.
This is something I've long thought that media players were really lacking. Things like Dune and the rest. Setup of those units was very time consuming and not at all straightforward. They didn't have a web interface, and they required third party software, with manipulation, to get a good media wall setup. It was... painful. Browsing, once things were setup, was easy enough, and worked well enough, but it also ended up being a fixed solution, so you didn't have h.265 decoding on older units, you just had to ensure your videos were all h.264 encodes (or similar).
I would think that Plex will be taking a serious look at 4K video and HD audio, especially considering their integration with Tidal. Saying "HEY! We do HD audio!" - Then going... "except if it's part of your video." is pretty lame. They need to ensure good 4K and HD audio is taken care of at the baseline.