It does seem bizarre that such places as Honiton will soon be getting more frequent services to London than Taunton!
apart from the fact that getting to honiton without a car or train is really no fun ,it is the closest station for most of east devon but it hardly has any parking ''connecting busses'' do not conect very well and are expensive and as it stops at 12 stations on the way isnt the ideal route to london unfortunatly
Most of the stations between Exeter and Salisbury are already much better used than you might think as they're railheads for the surrounding area. Gillingham, a town of around 9,000 people was used last year by 395,000 people - over 1000 a day. Honiton sees a fairly impressive 284,000. I think Taunton has pretty much an hourly London service at worst anyway, and normally better in the peak - there's plenty of up trains in the morning anyway.