The new blades makes a lot of difference, no more tangled threads and forever cleaning under the shuttle. BUT why is is so expensive? The one i got for my QE is only £6.99 , this 4 times that price. Pfaff have you over a barrel with this blade as you cannot just insert a craft blade knife as you can with other cutters.
Cannot fault the service from Couling, very prompt in answering my question and dispatched same day.