We had Fudge (now 2) spayed. We were kind of given the impression by the vet that it was really the only sensible thing to do. I now regret ever having it done.
For a start the operation went pretty hard on poor Fudge. She was allergic to the dressing they put on her, then reacted to her stitches. Second, ever since the op she's been flighty, nervy and barks a lot. Thirdly her coat is a total nightmare, she doesn't go a day without getting a matt, her top is thick and fluffly and horrible. Fourthly, at two years old and still getting as much exercise as possible we really have to watch her weight. Add those to the threat of incontinence in old age, countless other potential issues and we're left wishing we'd never let the vet operate on her.
I would say, if you can cope with two dogs you can cope when your bitch is in season, it just takes a little extra care. It's possible to have a contraceptive type injection I've heard and this has nowhere near the adverse effects that spaying has. A friend of ours, when asked about the risk of pyometria commented 'I've only her had one bitch get it and you just deal with it like any other illness.'
Personally I'd never have another bitch spayed. I understand why people do it but I think all to often we are not aware of the whole picture. Plus there's no real cause if your dog is already neutered.