Is OpenMapChest legal, safe, and good maps?

I like them, but I have only used United States maps from OpenMapChest.

OpenMapChest is based on OpenStreetMap data, thus it is perfectly legal. But define safe here. Safe is relative, as maps can have errors and the source relies on data from individuals rather than map companies. I feel they are good, and have used them in older GPS receivers that didn't have lifetime map updates, but I have no need of them as I no longer use my receivers that don't have lifetime map updates.

I used them for my Spain trip and they worked fine.

I use Open Street maps with Map Factor Navigator on my phone and have had very good results.

ok,

thanks