
Yes very often male cats are friendlier as a rule. :)
The thing is, a female cat left unspayed will get ovarian cysts after as soon as 3 years or so, and eventually will almost be guaranteed to get pyometra. It isn't like a dog, you CANNOT leave a queen unspayed without her being bred from -the health risks are much too high. Your average cat breeder will have anything from 3 to 6 or 7 litters from each queen and then spay her. Having one or two litters and not spaying is not an option. Having litters with 2-3 years apart is not an option. (And I do have personal experience of queens getting ill, from cats I desperately WANTED to be mated, but that for one reason or another refused to mate.) I recently attended a seminar for cat breeders/vets etc, speakers all top vets, and controlling oestrus in queens was one of the subjects, and the long and the short of it was, unless you control the calls by some means, the queen must be spayed sooner rather than later. The various way of oestrus control are not very good either. You can inject the queen like you can a dog -lots of possible side effects and the effects lasts 6 months so if there is a problem, it will be 6 months before the effects are gone. Hence this is not recommended. The pill -again risk of pyometra for instance with long term use. Or the only two options left, simulate mating the queen yourself with a cotton top (yes really), but this will only stop her for 9 weeks at a time, or have a neutered male that will still mate (=quite rare to find) and let him do the deed. None of this is good for long term use, and in the end you still have to spay just like you would a breeding queen.
The HUGE difference with female cats to female dogs is that the more they are allowed to call, the longer each call will last and the more frequently they will occur (it certainly isn't just once every 6 months!), so that you will be going from the normal of one call every 3-4 weeks (lasting 5 days), to a call every fortnight, until eventually you have a queen that goes into one continuous call and NEVER finishes. And as most queens go off their food when in call (and many will also start to spray of they have too many calls), you can imagine how much body condition they lose, on top of all other problems. (Again I do have personal experience of this happening. My very first show cat had 2 CCs and I was chasing the third, and she was of a breed that would become unshowable the older she got due t the colour changing, so I was really hoping for that third CC before she had another litter. Didn't work. She went into continuous call and HAD to be mated by the time she had been calling for 12 weeks, never got her third CC but stayed healthy instead.
So in summary, the risks of NOT spaying are far greater than the risks of the op.