APM elements last longer, however it's an expensive replacement if one fries due to a glaze drip or such.
I charge $75 per hour for repair work. A Skutt 1227 will take 1-1/2 to 2 hours to do a full element replacement. Definitely 2 hours if bricks are being replaced too, which usually there are a couple.
Different brands require more or less time. Skutts take a while because of the need for element pins, so in addition to the time spent putting in pins, I also have to remove the lid and top ring in order to reach the bottom ring and see what's going on down there. Paragon replacements are usually quicker because they only require pins if an element is being difficult, but some Paragon models have pricey elements. I can do all 9 elements in my big L&L in less than 1-1/2 hours. Manual kilns or any kilns that don't have a hinged control box take longer as well. Lots of factors at work.