The PIS on 175s was very poor when they were new.
They specialised in being one station out: This is Chester would be proudly announced at Helsby.
Nobody seemed able or willing to turn the thing off in such cases, as it carried on announcing Newton le Willows at Oxford Road.
Much more reliable now, but they are still limited by scrolling single-line LED displays.
On the other hand, 175s have always been cursed by multiple pointless generic announcements - litter, luggage, no smoking, mind the gap, SISIS* etc.
(*See It, Say It, Sorted).
Nationally, PIS displays are still sufficiently dodgy for no-one to trust them fully, hence the repeat questions to the crew about destination.
As with seat reservations, UK railways have never caught up with the continent on the reliability of train information, either on platforms or on trains.
It's worst on the ex-Regional TOCs who are still using primitive PIS systems on their old fleets.
Even the refurbished Northern 156s haven't yet got usable PIS yet.
Hopefully the new CAF/Stadler fleets will raise the bar.
Currently Thameslink (class 700) PIS is a cut above the rest.