Hi Dr.Zenttl I'm at the top of the learning cliff and looking down, just like you. I see from the picture you posted that you fly at Clover Point. I fly there Tuesday and Thursday nights (5:15 to hunger) When do you fly?
Good to have Terry look, or Mario! It's really a personal thing - the setup on your handles. Some use longer, some shorter. Some use lots of brake, others none. The leaders provided by Rev were a compromise between their no adjustments philosophy and John's attempt to give you even more knots to work with! John's leaders run 10-11" long with 7-8 knots! Those stock leaders were about 6-7"? with 4-5 knots? So as you can see, there are lots of variables in how you setup handles! Again - none wrong, just how you like it to work!
15" handles come in handy in really light winds - for some! I use 13", 14", and 15" handles depending on wind conditions of the day, kite used, etc, - maybe even my state of mind! Mostly use 14" - they've become my all rounders, 13" for strong wind, 15" for light. Really depends on any given day!
I also use a little different bend on mine - about halfway between the outdoor bend and the indoor bend. The ergonomics work better for the way I hold my handles and the amount of brake I use while flying. Many have picked up my stuff and can't launch it, wondering why I have it setup like that! But it is a personal choice - that's what is so nice about Revs - everyone is a bit different, likes things a certain way, etc. Just remember there is no "right or wrong", just how you like it matters!
You might grow into the 15", just use them some and see, especially in lighter wind. Experiment! Otherwise pass them on to another!