It amazes me that so many say they had trouble keeping their shower doors and track clean. I spray mine with KaBoom once a week and I have no mold, mildew, soap scum, or anything else in mine. Maybe, I'm just lucky.
Well, this is part of it, you are one person using the shower, try 5 people and spotty cleaning efforts. I do have to say that the daily shower sprays work well on the doors, etc. but it has to get done every day and not everyone here remembers .
Shower curtain liners are easy to clean, toss them in the wash with some bleach and white towels and they clean themselves. Put them in the dryer for 10 minutes and hang. Easy.
When we remodeled our bathroom, we took out the door and opted for a curtain. Maybe I don't move around a lot, but I've never had a shower curtain stick to me. The doors seem to get dated pretty quickly. I really didn't have too much trouble cleaning the door, but I never liked the look of them.