Bruno,
i have tried airflo- wasnt impressed too much memory,tried sci angler #4 darn coating is bumby and impedes smoth casting, tried orvis andhad issues with line cracking and peeling,i started out with cortland 444 and used em for years ,then i tried these others and blew alot of cash,then about 7 years ago i bought a windcutter by Rio for my big river fihing ( Lehigh,Delaware) and also bought their selective trout lines too i have windcutters in 4,5,6 and also a Windcutter spey 5/6 i use on my Gloomis Metolius Trout spey rod.for my money i'd stick with the windcutters or selective trout lines and then get a cortland 444 as a backup.In the Past from the moment i started flyfishing till 7 years ago i used double tapers exclusively,but my tastes have changed now unless i spool up a 444 i use only weight fowards,i recently picked up a Rio gold line to fart around with too ...jury is still out on that though because i haven't rigged it up and spooled it yet. And for a note the windcutter lay it out real delicately and the smooth pool browns and bows and brookies dont mind gettin fooled!
Tight Wraps & Tight Lines
Rick Wallace