Had a cheapish Hotpoint combo for 10 years with no problems / repairs anything.
The thing almost everyone gets wrong with combos is they overload - you can ram a washer full and it'll wash, but a drier needs space for the clothes to move around. They treat a combo like a washer and wonder why after 2 hours the clothes are still damp. Never fill more than half way and you'll be fine.
We've currently got a plain jane washer - was reduced from about 430 to 250 as it was from an old range, and make use of a couple of airers ... but then we're lucky to have a bit of space and we're both from the north so resent paying for anything we don't need to