I've been using these to pack hubby's lunch for years, since the days when you had to find them at the Korean supermarket (sandwiches can go into a Snapware plastic box, but if it's going in the microwave, I'd rather pack it in glass). I have yet to find anything superior.
Snapware is the US distributor, not the manufacturer, but they're not outsourcing to Korea - these were invented for the Korean market (and won an international design award), and Snapware, which makes its plastic ware in the US, decided they couldn't do better. They're providing awesome customer support considering they don't actually make the stuff - I managed to break the lid on one of the boxes, and they sent me a new one with minimal hassles and no questions asked (I sent them a picture of the broken lid via email - how cool is that?).
If you're having trouble getting the lids to go on: make sure the gasket is in the right way - they have a rectangular cross-section, not square, and if they get turned the box doesn't close. Some of the older boxes also had two different lid depths, and two gasket thicknesses, and if you mixed them up they didn't seal properly at all, but I think they finally fixed this. (And of course make sure you have the right gasket in the right lid - some sets are color coded by shape - red=round, blue=square, rectangle=green - but some aren't).
Besides that, no complaints. I wish they had a deep large round to use as a big noodle bowl (feels funny eating noodles out of a rectangle), or even an actual bowl with the snap-on lid. Given how popular these have become for lunches, maybe they'll expand the line.
