I hope in addition to the revamp that the NOW TV box resolves the stuttering playback issue.
From what I've read NOW TV - like Chromecast - only outputs at 60Hz. That might explain your stuttering if you're watching anything on iPlayer, which would be 25fps and doesn't go well into 60Hz. Some people just don't notice it, though.
It's on everything, from the Sky News and SSN HQ apps, to the NOW TV streams. Some of the live channels are more noticeable than others. GOLD for example has really bad stuttering ,poor lip sync and a grainy picture, while Sky1 is like watching a 544x576 Freeview picture with a low stream.
The LG set I own appears to have none of these issues as it also NTSC compatible.
I think you are missing the point.
All European TV is 50Hz. That means most streaming services in Europe are 25Hz (The BBC have occasionally provided a 50Hz stream for things like the Strictly 3D special - and have 50Hz streams for some other platforms)
The Now TV is fixed at 60Hz, like Chromecast, and the LCD displays of most laptops, iPhones, iPads etc. This means that 25Hz content is displayed at 60Hz - which means frames have to be repeated asymmetrically and you get motion judder that wouldn't be there if you were able to watch at 50Hz. Some people see this, some people don't (and given the huge number of people who watch 25p content at 60Hz on iPhones, iPads, Laptops etc. it doesn't appear to be an issue for many)
If you are using a Smart TV internal app, then the chances are it will display 25p streamed stuff properly at 50Hz - as the the TV will be perfectly capable of running 50Hz (aka "PAL") for Live TV viewing. (NTSC compatibility it irrelevant in this regard - but all EU "HD TV"s have to be 60Hz compatible to carry the "HDTV", "HD Ready" or similar licensed logos)
The major limitation for me for the NowTV box is the lack of a cabled network connection. If you live in a busy built up area, 2.4GHz Wifi is a non-starter for decent speeds, with 5GHz now often getting quite congested (and lots of things are still 2.4GHz only) All my kit is Ethernet connected with the exception of my iPhone and iPad (which are both 5GHz) and my Laptop (when not on my desk - where it is connected to a cabled network connection)