After using nothing but pencil jets since i started WFP over a year ago, i have recently over the last month been testing out fan jets.
First of all i hated them and did not feel confident with them, i just didnt like all the over spray, but i have to say a month down the line i wouldnt go back to pencil jets.
My Mrs has pencil jets and yesterday i picked up her pole and used it for one house and something just didnt feel right, so i guese im pretty much used to fan jets now.
I do however think that on very windy days i may just use pencils
Most guys on here are pretty split on the issue, at the end of the day i would strongly advise you to have a go with both for say a month each, because at the end of the day its only you that can answer your own question.
Hope this helps