That was my next question, do you guys that use longer leaders feel that you need to retie more often due to the guides hitting the knot while casting?
Nope dont really think it hurts the knot. I will retie the knot after catching a couple good fish though. I can't remember the name of the knot i use. But you basically make a loop in your floro then feed the braid though the bottom of the loop and wrap the braid down the floro 6-8 times then come back up the line wrapping the braid in between the other loops. Then put your tag end back through the top of the loop in your floro and you are set.
Jake, that is called an Improved Albright knot.
I prefer my junction knot to sit right off of my spinning reel, get the invisibility that way, the other benefits of fluorocarbon, so about 6 or 7' for me. On spinning tackle, I have never noticed a thing casting out. I occasionally feel the tiniest of ticks reeling in when the knot passes by the rod tip.
Too, 6 or 7 ft. gives you the opportunity to re-tie a few times.
I always tie on a fresh leader before each time out.
With really good fluorocarbon, don't be afraid to reel up a full casting distance plus some extra distance with a braid main line backing it up. Aaron Martens does this for certain fishing applications.