I don't wear shorts (varicose veins, scars from knee surgery, above all an aversion to mosquito bites and allergy to most sunscreens) so I don't like zip-offs. I prefer a pair of just plain nylon pants. The main problem is that pockets on women's pants are completely useless, and with my ample (!) derriere I can't wear men's pants.

You can get a pair of plain (not convertible) nylon pants plus a pair of lightweight nylon swim trunks for the same or less weight as a pair of convertibles, and you won't have to feud with the zippers.

Do note that this site is about wilderness trekking, not European style "backpacking = budget travel." Savvy backpackers (American style) take only the pair of pants they are wearing.