use copoly and braid, depending on the situation. I have two spools and can switch back and forth. The copoly is a mono core with a fluoro coating. Use braid for lily pads and heavy weeds, when worm fishing. Use copoly when throwing lighter lures and topwater fishing.
i do as well. i always use the copolymer with fluoro coating except when fishing the pads and slop. then i use braid.
why do people only use braid when fishing in the weeds? what's the advantage of using mono or flouro or copoly when fishing lures?
braid is strong and sharp so it will easily cut through the weeds without snags, tangles, and damage to the line. it's basically easy to fish in the heavy stuff. one negative is that it is generally more visible to fish so it's tougher in clear water or open water. if this is the case, most people put a fluoro leader on the braid. if you're pitching jigs into tree branches or something like that most people will use braid or really strong fluoro instead of mono which isn't as tough.
the other "clear" lines are generally an all around line but not really suited for the heavy stuff. mono has more bend or memory than fluoro so a lot of people use it for topwater or even when cranking. setting the hook is more "forgiving" than when using a stronger, less bend line like fluoro. people sometimes find 100% fluoro too stiff and hard to cast especially on a spinning reel. i believe it sinks faster too.
i have a feeling heron is using something like P line floroclear which is the copolymer with fluoro coating. i exclusively use this b/c i think it is the best of both worlds (mono and fluoro) - it is stronger than mono, it is nearly invisible under water, it has almost 0 stretch and memory, but it isn't as stuff and hard to tie etc.
i know i'm missing a lot of points in here but that's sort of a general idea.
these links give some good information
http://www.basspro.com/webapp/wcs/stores/servlet/CFPage?mode=article&objectID=29436&storeId=10151&catalogId=10001&langId=-1
http://www.basspro.com/webapp/wcs/stores/servlet/CFPage?mode=article&objectID=31231&storeId=10151&catalogId=10001&langId=-1