I have just gotten an Exp 3.0 and love it. All except for the presser foot lever at the back, but then I have that gripe about every sewing machine.
I can't get needle threader to work, but can easily do it by hand. I've figured out most of the machine. Yahoo.com has a web site for Pfaff owners. Sorry, can't remember name but maybe they can help.
All else fails I'll happily trade you my 3.0 for your 4.0. Just to save you frustration you understand!
Good Luck!