For me, it's the swipe navigation that means I can browse one handed. Do wish there was an ultra compact mode though, little too much dead space on the posts screen for me. I like it DENSE.
I don't keep 4k content, I find that 2k encodes for the stuff I really want at high fidelity is enough with Nvidia upscaling (Nvidia shield). Plus surprisingly some of my 2k files are no larger than 1080p.
All my content is converted to CPU encoded x265. Size is MUCH smaller and quality better than GPU encoded x265. My preference is to get remux copies of the content and then encode it myself.