> I have a rare brand loyalty for the brand of box I use - only the "Really Useful" stacking boxes.

Same here. I've been using them at home and work for years and they are absolutely fantastic; we've probably got well over 100 and it's rare for one a year to break and even then it's usually just the lid.

I think they've been very clever in how they manage their range. I generally use the 12L and 18L boxes, but I don't need to remember any dimensions because a different profile box would say be 11L or 19L. All you need to do is remember the capacity and it'll be the right matching box.