I have been using Nvidia shield for last 8 months. Got it from US as India availability was a big issue. Initially thought of getting Firsestick but later settled with Nvidia Shield for more versatility. Neither my TV nor receiver supports 4K so will not be able to comment on that.But current gen does not have support for DV.
But I would like to know from Indian angle. How is this device specific to India? I mean how is gaming console feature (kids like basic games) in India? How about streaming services specific to India? Most of all services available? Any India specific restrictions?
From Indian usage angle also this device is good and we can download and use apps from google play store like Hotstar, Sony Liv, Zee5 etc . But do remember that play store is android TV specific and several apps from mobile playstore are not available. There are some Firetv specific apps which are not available on play store like TVF, Voot scoopwhoop etc but can be sideloaded and they work fine. A good thing is that several apps not available on app store officially can still be sideloaded.
But do remember there are several country specific content/app it will not work here. Few I tried were Vudu (app is there but does not work). Some apps are not available at all in India like BBC iplayer (tried to sideload it but was not able to make it work), Disney app (cannot recall exact name now) + few more.
Playing content from hard disk is great. I tried playing 20GB files and those played very well. It comes with Plex media server and MX player, VLC can be installed for playing local content.
Gaming performance is best out there (in Android TV world) , in fact one of the main reasons for getting it. Gameplay is smooth. If gaming is required do take version with shield game controller its worth small premium paid. Else third party game controllers are also available. I was using with my PS3 controller and it worked very good. What is know PS4 and Xbox controllers are also good option. but dont go with cheap 3rd party controllers. I tried few and those were not good and spoiled fun. I am currently using with Logitech F710 performance wise it is good but needs a dongle to be connected.
It also comes with Geforce now with several free games and steam games can also be played. I had tried anf games though run fine but primary issue is with latency. For slow games its not noticeable but for fast moving games that will be concern.
One more point with android games is that since device is having 12 GB of usable storage which is fine for normal use but if we install huge games then space will be filled very fast.