Have had a few years now using both, and imo I just prefer trad. I'm forever getting the hose caught on things and it can become very frustrating, the maintenance also costs more, having said that I find WFP brilliant for con roofs, fascias, gutters etc and it does do a good job on the windows I just prefer trad.
Anyway, with this in mind I am going to save up some money for a while and start up on my own initially trad, may purchase a backpack kit later down the line for one-off jobs such as con roofs, gutters etc. This will mean it will be a lot cheaper to start up to get all the trad gear and I will buy a cheap, reliable van (any suggestions?). The only reservation I have is that is there enough work out there? The area I live in is quite saturated with window cleaners already so I have a bit of a question mark over this but still remain confident I can get the customers.
Any help or suggestions appreciated.