I've been in 3 or 4 times before. On a previous visit an employee (not at the window) noticed how long the line was and stepped in to help speed things along. This was great! Most branches don't seem concerned how long the lines get.
Today, I went in to mail a package and didn't have tape at home. I need about six inches of clear packing tape to seal my box. Instead of using the roll on the counter, the clerk said I had to go buy some. I know stamp prices continue to rise, but every time I've mailed a package in the past they have inspected it and usually added tape to mine.
Guess it depends on who is working that day whether you'll receive great service or poor service.