just curious.
with all the advancement in smart TV's -- it's capability to play media from external storage devices + it's capability to stream online -- is it still viable to buy an NMT?
if yes, why?
as you've mentioned all the advancements available in SMART TV's, i believe you have covered DTS-decoding. because yes, this has been mentioned above that not all TV's (means NOT or SEMI-advanced? hehe) can decode DTS. make sure that the license is DTS Surround and not just DTS 2.0 or DTS Digital Out.
I will only say yes, you need an NMT if you go the route of ATMOS/DTS:X. because only the upcoming LG OLED 2017 models promised they can decode ATMOS (but still not DTS:X).
if you'll not go ATMOS/DTS:X, I strongly suggest you get a Sony Android Smart TV, it can also become an IPTV and an Android game console.
and if ever you'll get yourself an NMT, I strongly suggest NVidia Shield. it can be a portable IPTV, a media player, streaming device and a game console all-in-one =)) a match made in heaven to any TVs (SMART or non-SMART, alike) + the ATMOS/DTS:X pass-through =))