I think the boys are actually easier to housebreak than the girls ( my own experience) and never had marking with 5 males over the years. I don't even let them pee on things when we go on a walk unless I tell them they can.
Urethra of a female is shorter than of a male, that's why it is easier for her to empty the bladder. But, even so, she has to pee twice at least in order to have some relief, because dogs are territorial creatures and God created them in a way that they cannot pee out everything at once. Urethra of a male is longer and it is more difficult for him to empty the bladder in a short time, he has to raise his leg ten times at least. For the same reason it is more difficult for a female to hold the urine, she goes on the grass straightaway from the house, while the males don't pee until you bring them to their "marking post". Concerning this, you better plan the route for your male puppy, though they start marking not earlier than 10 months old (they pee like girls before this age). If a young male marked at home, you can be sure you have encountered his psychological problem. He might feel very insecure being bitten by older stronger dog, you should try to avoid such accidents as much as you can. By the smell of urine the male knows everything about its bearer - his physical state such as health, his sexual potential, his size and even his age. If your friends, who have a big male, come to your house - your dog might mark their clothes and shoes.
The males are known to mark the legs of their owners in the doggy park when their beloved master petted another dog. The male minds you as his own property. Other males might pee on you or on your bag just to irritate your dog.
I knew one unmarried chap who was very keen to get acquainted with yet another girl. He hadn't much success because of his dog who peed on girls if he liked them.
I've had several unaltered boys who were a snap to potty train and didn't act any different than their altered counterparts.
The only...spraying...I can think of is the gifts that, unaltered boys especially, like to leave behind after a good nap; nocturnal emissions. It's a natural, normal thing that can and does happen. I've seen/heard of altered boys doing it as well, but not with the same frequency as their unaltered counterparts.
Wow, I feel the need to say that there is a certain poster on this forum who has a vivid imagination that he likes to pass off as reality!
I have shared my life with both male and female dogs. The only dog who marked in the house was an adult foster dog and he only did it once, on the first day I had him. Two of my females were much bigger markers than males. And everyone should know that you can train your dog (male or female) NOT to mark! Rafi is not allowed to mark while on leash. When he is off leash he can mark to his heart's content.
Also, lots of male dogs never mark!
As for spraying: both female and male cats spray but it is usually out of the house!