I've spent the last week Travelling on XC Travelling between Birmingham new street, Exeter,Bristol and Cardiff, 1st leg of my travels was between Birmingham and Bristol (*) on a voyager, thought it was going to be packed with people but there was ample room to sit BUT when i did the Journey between Bristol and Exeter (**) (On a Voyager) i had to do a "corbyn" along with another passenger and sit on the floor as there was no seats until Taunton.
On the return journey i went between Exeter and Bristol, on a HST and it was busy ,but there was loads of Room,plenty of seats and no one standing, although i did poke my head out of the window a few times for old times sake
The Cardiff journey back to Birmingham (On a class 170) was busy but there was a few seats, which leads me to this.
Echoing what
@DarloRich has said, Surely it would be better if XC had longer units on the busier routes (maybe Refurbished HST's like scotrail are doing or indeed order newer units like a 800) and put the Voyagers onto the lesser used routes between the cities and put the 170's on shorter local routes, i know i was travelling with people who were either going on their jollies (or come back from them) and few business types, but it's no fun at anytime of the year being crammed in with not much space!
(*) (**) And i remember doing this journey quite a bit in the late 80's and early 90's when i was a kid, and this route was ALWAYS a HST, busy but there was never any standing and we always travelled in comfort!