There are a couple of Roku OS 9 features that appear to have filtered down to NOW TV:
Automatic Volume Leveling – This feature enables a uniform audio level across various types of content, so it will no longer feel jarring when a commercial comes on or when streaming channels are changed. This feature can be turned on/off within the Volume Mode setting that appears in the options menu after pressing the Star button “*” during video playback.
Control enhancements – Customers can now control media playback using their voice to pause, fast forward and more. When using voice search and control, customers will see a new heads-up-display (HUD), as well as receive audio feedback, to provide confirmation that their voice intent was understood.
Also OS 9 saw the return of Spotify to Roku, so with a bit of luck Spotify will also eventually appear in the Now App Store.
I ditched my NowTV box a long time ago for the flexibility, performance, and extra content a Roku Streaming Stick+ brings to the table. I've never been a fan of stripped down devices provided on the cheap by the likes of Sky etc etc.
Since updating my now tv smart box with freeview to software version 9.0.3 beta 4070 I have seen major improvement in picture quality in free views channels and now tv channels and less bugs in the software. Just waiting for Spotify app to appear on the now tv store.
It will update automatically BUT if it's been announced that a new version is available you can also manually update to get it that bit quicker.
There is no manual involvement in 'installing' the software as it's an update/install process all in one.
I'm surprised you've asked such a question simply because you are a long time user and as such should know the answer.
Anyhoo, here we go, all Now TV updates auto-load unless something goes wrong and then you are advised to manually download and perform the update yourself.
My problem with these updates is you are never told when they are supposed to happen, what bugs they are going to fix, what new features they going to bestow or old ones they are going to delete.