i wouldn't say its crap, but you'll get a better gloss straight off the gun with 2 pack paint. The down side to 2 pack is the isocyanates, so you need to use a air fed full face mask when spraying.
If its too cold the dulon will 'blush', if its too hot it dries to quick and you can get dry lines, you really need to chase the wet line with it. The plus side is it dries quick. But you'll need to buff it to get a really good gloss and it's not as hard wearing as 2 pack paint.