The trouble is they work and then don't, there's no warning.
Mine failed at just under 6 years and just over 30k miles and leaving me stranded in France
Rather annoyingly I was with ShaunD who had a spare pump and PaulR who's changed his a few times. However as the engine just cut with no preceding loss of power or stuttering before changing the pump we did some tests and there seemed to be plenty of fuel pressure from the schrader valve but no spark so I thought it was electrical/ECU.
I was in the "do I really need to change this" camp but now would definitely recommend it as a worthwhile precaution.
