If you are worried about the fathers nature, IMHO, I don't think you are going to enjoy your pup in the same way.
I agree too.
Even though i consider myself to be an experienced dog owner i am quite worried of buying another puppy because it really seems to be a total minefield.
For example, after months of research & questioning it transpired that the grandsire of Jo Jo's 1st litter has behaviour problems
this only came to light after 2 pups from our litter of 9 (one is our Nina & luckily a close friend has the other) has behaviour probs & on delving deeper found this info.
I do feel absolutely sick that the owner of the sire is 'pimping' him out in full knowledge that his dad has these probs
This dog has sired countless litters....when i have asked it always seems to be 'oh he's had 6/7 litters already this year'
I despair.
I am being brutally frank here but this person is a member of the Cocker Spaniel Club with numerous years of breeding & showing.
My personal hopes & dreams (originally) was to start my own lines with Nina but of course that is impossible to do now.
It is totally unfair to pass on nervous, grumpy behaviour to any other puppies.
Sorry i am going slightly off topic here but just trying to show examples of how 'scary' it is trying to choose the right pup. Behavioural problems
can skip a generation & most people don't have the benefit of knowing previous generations in the line.
Naive of me, i know, but really wish that all breeders were totally honest & straightforward.