Honestly, if you are comfortable with the idea of spay-aborts, then that is the route I would personally take. I didn't know much about them and how bad the population problem was until a recent IMO thread on spay-aborts and it's really opened my eyes to the problem. If I had known about that option in time for my girls, that is the route I would have taken even now that I have the kittens.
My reasons why: 1. it is much more costly to raise 11 kittens and be responsible about them ie. spaying/neutering each kitten before they find new homes.
2. What if I can't rehome 11 kittens?
3. It is much healthier for the mama just to spayed then to have kittens.
4.The overpopulation of cats and dogs
5. thousand upon thousands of kittens and cats are put to sleep each day. If I didn't have 11 kittens now, I could be potentially be helping another cat/kitten who would be put to sleep.
I don't mean to push any of my ideas onto you. I think you should do what you are comfortable with. I wish you all the best in making such an important decision (and tought too).