[Stooky Bill]

Does the average listener know or care that it's not a "true" national station?

They don't, unless they want to listen while moving around. 

Where I live you can just about get it on FM from a nearby regional station and in three big towns nearby they've taken over their small local FM stations. 

Problem is they don't quite overlap and they haven't activated the AF function In RDS so driving around listening to requires manually retuning. We have 3 presets for GHR.

Very different to Radio 2 which you just tune to and listen, no faffing about or gaps in reception