I had a PEG and we were initially set up to do overnight feeding. If I remember correctly I used it once or twice and then discontinued it and just did it by myself with the big syringe. (I did not have problems with the speed using the syringe method).
For the overnight feeding you want to be sitting up a bit (pillow). I am sure others who used the PEG extensively will pipe up.

FIY. there is also something called benecal that you can feed via the PEG it has a very high calorie content per volume and appears quite oily.

M