So I’m wondering if Roger ON in streams audio directly into the aids - hence the “outstanding” sound? HOPE SO! 
Yes. It’s the same proprietary Roger protocol as in the TV Streamer. In fact with the optional charging dock the Roger On can function as another TV streamer. Charges fine without the dock via USB-C.
It’s a pricey accessory, you can almost certainly do better online. Adding the “receivers” to your Lumity devices is easy. That’s where you will have one hiccup. The "iN’ devices cost more because they come with two receivers. It’s really just software that transfers to your hearing aids. You see where I’m going with this - you’ll only get two, so also add to your spare set.
That said, it’s easy to uninstall from a hearing aid and install to another. Alternatively, you can get cheap universal Roger receivers on eBay so you can do all 4 of your hearing aids.
It sounds complicated but there are videos showing all this on YouTube and once you see it in action it’s really simple - just a series of steps. Happy to help.
Roger On is awesome for loud restaurants, family dinner table, conference rooms. Even if it didn’t connect to my laptop for Zoom meetings I’d still love it.