So far my experience with Apple TV 4 has been awful. Just awful. I can honestly say I actually miss my old Apple TV after using this one for three days, which is bizarre for an early adopter like me.
1) Remote app doesn't work with Apple TV 4 at launch, which makes #2 worse
2) Setup sucks. Without the remote app, I have to type in all my passwords for all my services like Netflix and Hulu with the awful on screen keyboard.
3) Apps like Hulu are inferior to their Apple TV 3 counterparts. The new Hulu app is terrible compared to the old one. It looks awful and doesn't remember the latest episode you've been watching in an older TV series. Not to mention it crashes frequently, requiring you to restart the Apple TV
4) Bugs - as mentioned in #3, my Apple TV crashed frequently when watching Hulu, when I went to restart I saw pink pars across the screen for several seconds before seeing the Apple logo. It was reminiscent of the BSOD on Windows, which put a bad taste in my mouth and shows no real testing was done with 3rd party apps. In the industry we call this the cost of poor quality when trying to rush a release.
5) Feautres - Siri doesn't work as promised - results weren't showing me only the services I'd subscribed to - but rather everything available to purchase or subscribe. Additionally the 'what did he say' function only works with Apple's TV and movies. If you try this in a third party app like Hulu, it won't add the captions temporarily like it's advertised.
6) Interface - the new UI has gotten a facelift but I hate - absolutely HATE the 3D cover art swivel that you get when scrolling between menu items. It adds unnecessary 'friction' when trying to scroll between items, which is bad - this feature is even present when scrolling through letters on the keyboard. Who the hell needs 3D swivel for the letters? Are you kidding me?! Also, the 'top menu' of Purchased, Top Movies, etc. disappears when scrolling down, making it confusing on how pull it up again in order to navigate between tabs of content
7) Remote - this one is surprising but I don't like the placement of the menu button + TV button. I find myself accidentally hitting the Siri button as the menu button and vice versa. It would feel much more natural if they left all of the buttons off of the touch trackpad and moved them to the lower part of the device, making it easier for your thumb to hit. Having them so high up feels like a bad compromise for them trying to turn it into a gaming remote. Also, despite me having a brand new Samsung TV, I couldn't get it to work to power my TV or change volume - I suspect this is because I have my Apple TV fed as an input to my XBox One, so it throws off the HDMI-C thing but as of now I have 3 buttons on the remote I cannot use for anything.
I tried to like the new Apple TV, I really did. But in its current form, it really stinks. This doesn't seem like a high quality, polished Apple product that I've come to expect.