Personally I prefer Stagecoach's approach where every route is treat the same bar a few gold routes which are longer routes where you're expected to be on the bus for longer travel times.

Once you start doing stuff like the X Lines and Sapphire you end up having a mixed image imo. By this I mean that some bus routes are treat like a special route and get all the attention yet if you don't live on one of these routes you end up with nothing and usually resultingly: older buses, no features, no special fares (more expensive), crap service, bad / no evening service.

By using Stagecoach's approach everyone is treat the same, no special route fares, all buses are the same (okay newer ones might have NSA etc) so it gives off a uniform brand across the board. GNE for example if you live in Birtley you have the 21: new buses, much cheaper, 15 minute service, direct to Newcastle. Live 5 minutes West in Ouston you have the 28: older buses, expensive, no evening service til recently, goes around the world, .

That's just my opinion though.