The good bits -
The diesel engine has a fair amount of poke, especially compared with a 153 I traveled on between Derby & Crewe - 0 to 60 in over 5 minutes, when it had to stop again!
Toilets are present and normally work - The motion of a Pacer works a treat!!
Far better than no train!
I like the 3 + 2 seating. More people can sit and legroom is not bad. A friend is 18st and you can still sit together!
Saving Branch lines - lol They were 'designed' for Cornwall, Devon etc, and most branches there are unsuitable for them. Tight curves, steep inclines, resulting wheel slipping, excessive wheel and rail wear.
Going over worn points is like a pot hole!
Originally they were going to refurbish a load of first generation dmu's at Swindon, but a decision was taken to close Swindon Works.
Imo Pacers were a cost cutting, short sighted mistake. An era of 'penny pinching' economies forced on BR by HM Gov with single track, removing loops, and crossovers and closures.
I don't know the difference in price to build a 70mph dmu and a 90mph unit,
but eg joining a mainline with a possible future 100mph speed restriction eg Kirkham to Preston on the South Fylde line could cause delays.