I'm curious what's it like on the 170s between Birmingham and Cardiff experience wise? Deciding to go on one of them instead of TfW to Cardiff from Crewe.
I commute from Lydney on CrossCountry once a week, either to Cardiff or to Bristol via Severn Tunnel Junction, and also travel occasionally to Birmingham. They are almost alway on time, with better punctuality than TfW. They can be very busy, particularly between Cheltenham and Birmingham, but Cardiff to Gloucester is generally okay.
The 170s are comfortable and have nice large windows, and a good HVAC system, I don't think I've ever been on one with broken air conditioning. They are in desperate need of refurbishment but staff are very good.
The only thing holding them back has been the regular cancellations however that seems to have drastically improved since the new year.