Purple Orange
On Moderation
And this is where both personal preference and opinion comes in again. They (in particular the GW) do look cheap inside. Or perhaps you enjoy the lighting experience of a dental surgery?
They may lack the squealing of a Mk3 corridor, but I find the wind noise far more annoying on an IET - particularly the constant droning if you sit in the leading cars. Something I don't experience on any other modern EMU.
The 180 was only being used as a point of "All enthusiasts rubbish the new and long for the old". They are, somewhat unfortunately, not as successful as their far more disliked contemporary of the time.
Yes this is all completely personal preference. I've not been on a GWR IET so perhaps my view of them could change if I was to use one.