We have a PS4 but like you said unfortunately it doesn't support YTTV.I'm a PlayStation guy myself. Was hoping YTTV would be on PS4, which would give me reason to buy it.
CF, I found this comparison of Roku Ultra and AppleTV 4K earlier today.
I guess my thing about that review is I'm not going to be starting and stopping applications on either device. I'll just be using the YTTV app and once it loads that's it. I won't be switching back and forth between apps so the fact that the Apple TV has a better processor is kind of meaningless for my use case. I also do not have or use iTunes so have no need for the Apple ecosystem apps installed on the ATV. I could definitely see how the ATV would be better for some but I'm going with the Roku Ultra. Not sure there's much of a difference between the two for my use. Also, I can get 2 Roku Ultra's for the price on 1 ATV. I have 2 TVs I need a streaming box for so that also makes more sense to go with the Roku's otherwise I'd be spending close to $400 on hardware. Which one are you leaning towards?