Well, I have a female dog who is spayed because current evidence suggests that is best for her.
Both my bitches are spayed - I like them to have a couple of seasons first (this is a personal preference) because I like to think that they are fully mature physically and emotionally before neutering but I would always spay a bitch. The chances of pyometra, and of uterine or mammary cancer are hugely increased in a unneutered bitch - and of course, there's always the risk of pregnancy, no matter how careful you are with her when she's in season.
My springer was spayed at 17 months having has two seasons. My cocker was spayed at 16 months even though she hadn't had even one, because I and my vet were concerned that she might be having "silent" heats (no obvious visible signs, but still releases a pheromone which attracts male dogs, and can still get pregnant). I didn't want to risk this as puppies are a huge responsibility. She was from a litter of 11, and while I could possibly feel confident of getting good permanent homes for three or four puppies (not that you can ever be really sure), I wouldn't want to risk getting left with that many puppies because I didn't trust the people coming to view them.
My puppy will be male and assuming there is no sex aggression or inappropriate marking he will be staying entire.
Same here. We've left our male dog entire, and he will stay entire unless he starts to make a nuisance of himself by running away for lady dogs, or random shagging of cushions, people's legs, the cats etc.
Testicular cancer isn't such a risk; and I wanted him to become fully physically mature - and as a PP has pointed out, that means good strong bones and joints. He's 22 months now, and has gone through his teenage "shagging the vicar's leg" phase and is settling nicely.
Our spaniels are a working springer and two working cockers.. There are many breeds where he buyer has the option of show-type or working-type, not just spaniels. (eg labradors, GSDs, viszlas).
Personally I would always go for the working-type, from a good reliable breeder. Why? Because there isn't the pressure to conform to a "standard" with regard to appearance, at the expense of health or temperament.
A working dog needs to be healthy, sweet-natured, easy to train and biddable - so that's what they breed for. If one pops up which is physically a dream, then that's a bonus.
However all of mine are bloody gorgeous, bright, good-natured and well-trained (well, the dog's a bit of a cheeky bugger
- but I like a bit of mischief).
I think flat-faced breeds are very cute to look at, but I wouldn't have one because of the health problems previously mentioned. It's cruel. Simple as that.