Just joined today,and am a professional window cleaner here in the UK, and still useing the traditional methods, at the moment, but sometime in the future, I will be changing over to the water fed pole system.
I would just like to say that when you buy your product from your local suppliers, they are not always clued up to your type of work.
the sales guy, may be able to show you how to hold your squegee, and he may be able to show you how to use it. but it takes months to master it, if your new to the squeegie, then I would suggest to you that you use the straight down method, and after each stroke, wipe your blade (squegee) this will stop the line's you can get, I don't know if you guy's use scrims for the final deatailing, but if you do try to keep down the amount you put it on the window. you will end up with bits all over the windows and a white cloudy residue, the only way to get rid of it, is to wash the window again. I hope this little bit of info helps.