I have not travelled enough to compare 377's fitted with ironing boards and 387's to 700's. I am just glad the longer part of my journey is a Chiltern 168. ( I've never used a train booked for a loco and stock to/from London only for 30 mins or so at the north end of the route ).
While the average journey time on a 700 maybe 20 minutes and as a proportion the number making the full end-to-end journey small significant numbers travel for an hour or more. This was known at the design stage given they were class 319 replacements.
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@Steve Harris I have found Brighton-London is more than enough, just like the 387's.
While I've not been on a 444 I agree there should have been two variants.