I think that a lot of these kitchens are only as good as the person installing it.
We have an Ikea kitchen that Dh installed 7 years ago - the cream shaker style one, can't remember what it's called - Adel??. Anyway, DH not a pro but he is an absolute perfectionist and spent ages making sure the doors were lined up perfectly, drawers where spot on, hinges were perfectly balanced etc etc, and it has lasted brilliantly and still looks almost brand new.
I've seen friend's kitchens that weren't installed so well and doors look wonky etc, and it looks awful. All it probably needs is someone who knows what they're doing with a spirit level and a screwdriver to tidy it up no end, yet people write it off as 'badly made' or 'poor quality'.
IMHO, all these kitchens are much of a muchness when it comes to build quality, but the difference between an average kitchen and a really good one, is in the fitting.
And to give another perspective on Ikea oak worktops, we love ours. It looks great and we are very slack about oiling it. I think we last did it before Ds2 was born - he's now 2.8 