1) Doesn't allow negative receipts. I don't want to have to enter what essentially is the same kind of data in two different places.
2) Once you have started to enter a receipt, it must be posted before you can exit. If I was entereing ten items but had to get out halfway through, I would have to post and then start a new receipt when I came back to it.
3) Takes longer to manually enter a receipt than an adjustment (but importing is the same).
4) Receipt number can't be a default field. (Petty, but not sure why you can't).
5) Help says you can't delete Completed receipts but you can.

Biggest reason is number one. I had tried using receipts in the beginning but it was easier to do everything in one place.