catch cans that have a drain or can be opened are not emmission law friendly. the catch can we make for the srt4 is sealed and therefore legal. when you empty ours you just remove a hose and turn upside down to drain. we have pondered making one for the 6.1's but are still looking for a good spot to mount it. as to the hot vs cold, a cooler then engine temp catch can will trap more oil as the oil mist hits the cooler sides of the can turning the mist vapors back into liquids thus traping them in the can. when your engine ingests oil mist, it reduces the octane # in your gas causing you to lose performance and might increase knock....
