Your right they have big heatsinks, but they are encased and they are passively cooled(no fan). They hold a lot of heat. Nema 4 is a weatherproof enclosure.
Does the guy load trucks? Or actually builds the lights? Most warehouse guys I've known aren't to knowledgeable, that's why 5% are damaged during shipping lol . There's one thing I'm 100% sure about and that's electricity. But that's just wrong info, surf around all the sites you can find and just show me where the Cree, vero, and citizen chips have a high tendency to burn out. That's why they have long warranty on chips. I'll ask the rep at work what percentage of cob lights, that gets toasted in first 2 years, he should know, he's the one that has to replace them.
I'm not trying to be cocky but I've installed 1000's of outdoor led lights in past 2 years alone, not once have I gone back to replace one. Had many bad photo cells, or just broke in shipping.
Thanks for liking the grow