Typically, females are cleaner, more energetic, and smell less.
Typically, males are more lazy, have a higher chance of being aggression (because of hormonal aggression which a neuter will solve), and of course as you said, mark more.
People have said females can mark, its just more likely with males. I've only had 4 females, none marked. Females are more likely to get tumors (mammary tumors), which I believe there is like 80% chance of a female getting one once they're over two. Spaying cuts that WAY down. If spayed they're not likely to get one.
Most of my males arent lazy. They're active and dont like to cuddle. However, all my females were OVERLY active. Always hyper, always on the move. One of the girl did like being held, but never got to cuddle with any of them. I only had 4 females, though. To where I've had over 20 males. Probably only about 10 of them would like to cuddle (I usually take in the aggression or extremely skittish rats, though. That could be a factor as to why they didnt/dont like cuddling).
I have all males right now, but miss having girls dearly. When I get some one day I'll definitely be spaying them, 2 of my 4 girls got mammary tumors. With spaying being basically a prevention, I dont see why not to get it done.