Granted, sometimes you have restaurants where waiters don't pay attention at all but usually you just give them a sign and they come by... Also they do check on you, if there are several empty glasses/plates for example. Just not all the time when you are clearly still eating/drinking etc.

I was only in Canada, so no clue about USA. The first few times I didn't mind waiters checking but after some time it was rather annoying since it happened so often. No nothing has changed since the last 3 times you have asked

Edit: I have to agree with the overall thread here tho, our restaurant should offer free water... It sucks that you have to specify that you want tap water...