Unique
depends what you do on it, but the 4k firestick with kodi sideloaded is pretty good in that it runs netflix, amazon, and youtube in 4k (cheap chinese boxes often don't let you do all any, nevermind all 3 in 4k) plus kodi will let you do 4k too. it'll also do most of the catchup services. main difference if you can live with sideloading is the sheild will do gaming better, but i don't use that feature
I use Kodi the most on the Shield to pull across downloaded content off a local server, and then drop back to Android for a couple of IPTV services and the odd Netflix, Prime, Youtube etc, but I do also use it a lot to stream gaming across from Geforce card in a gaming PC in another room which is why I've stuck with them.
I did grab a 4k Fire stick on Prime day for about £25 the other day but have that ear marked for a family member.