I have noticed that the time it takes for miles to post significantly varies and always gets anxious when I am not given instant gratification.

Delta Skymiles usually posts by the time I arrive home and certainly by the next day. US Airways usually takes 5-7 days to post.

Starwood Hotels seem to post within 3-5 days for the stay but have great difficulty having my Platinum 500 points amenity post and I often have to call both the hotel and corporate customer care to get the points.

Marriot usually takes about 7 days to post in my particular case.

Dollar Rentacar takes about 3 weeks to post to US Airways.

What experience has others had with miles/points posting from hotels, car rentals, and airlines? I was curious if it was consistent within a particular program, if it varies for individual travelers, how often miles DON'T POST for an individual when you qualify for the flight and/or stay, and if it matters if you are an elite member or not?

By obtaining everyone's input about the various programs, we can get idea on how long to wait before calling customer service.