Maybe I was just unlucky. And as you've said they were very good at replacing stuff and supplying missing bits.Fitted two wren kitchens this year
1st missing a couple of handles
2nd damage to one unit and needed two extra end panels due to design error. (Didn't mirror wall unit end panels on the base units cocking up symmetry with the cooker/extractor.)
Quality was good. Spare parts was days/week and plans/labeling was superb.
Years back I fitted an MFI kitchen, when they were at the peak of being knocked by everyone, but I had no problems with them.
Luck of the draw I guess.