Depends on your experience level, or if you have ever been shown how to clean a window properly.
I have met several window cleaners that use straight pulls and cant use a trad pole, yet they make a good living.
I have been cleaning window both trad and wfp for over 20 years (on and off) I started at 15 and was taught by a very professional window cleaner who is still cleaning windows to this day, and I have to say that I learnt a couple of things I didn't know so for me it was worth it
hope that helps
