I'd like to say that my Hotpoint is 7yrs old... ...but trying to think what bits are still original 
Where as my hotpoint is 15 years old and just fine, having already said, hotpoint top end (ultima) models are exactly the same as Bosch.
I have mixed views of Bosch stuff, my Bosch oven is rubbish and yet expensive, Bosch power tools are middle of the road and the tumble dryar seems ok thus fat. Hence research required as the brand does not guarantee quality
My previous dish tosher was an Ultima, but was actually hopeless. Not only reliability, but the actual wash performance was poor. Hotpoint said it was OK when it was under warranty. I replaced the spray arms, as the top one in particular as a bit too sloppy, but it didn't improve, and I wasn't prepared to change the wash pump on the off chance. So when it went wrong again, I just replaced it.
I think it was just a poor model. I think too much emphasis to get it energy efficient at the expense of wash performance.
The one I have now still has poor reliability, but its wash performance is good, so worth repairing when it goes wrong.