Hiya. I would say, get them done. Female rabbits are REALLY prone to ovarian cysts and uterine cancer and of course spaying will stop this. Also they get incredibly hormonal and can get quite aggressive, not like being handled and scratch you. This is of course as they get older. Spaying will stop this too.
The cons are few, you obviously have the cost of doing it which is probably about �50 each but get a quote from your vet who will tell you exactly how much this will set you back. Also there is a risk with all anaesthetics but these days you don't have to worry too much as they are very safe.
If it were me, I would get them done, the pros definitely outweigh the cons.
Hope it all goes well