My boyfriend is a big drinker...not an alcoholic, but he drinks a lot of whatever he is drinking, whether it's Dr. Pepper, water, etc...so it is really annoying when they drop the bill in the middle of the meal and disappear. No refills, no desert, no more attention from the server. I have worked in several restaurants, and know that it can get busy, but I was always careful to not neglect a table.
This may be a little off topic, but the other weekend my friend and I were at a bar, and we started a tab. Sometime around 11:45, our server disappeared. We didn't even see her again until 12:30, when she was getting the bill for another table. Then she disappeared again. I ended up having to go to the bar, explaining to the bartender we started a tab and our server was MIA. 10 minutes later she came and gave us our bill. We left immediately after that, at 1 am. I was so ticked. I thought that was really poor service.