I guess I was just unfortunate enough to buy a new Kitchenaid Dishwasher in about 1980-81 when they had newly added the second spray arm under the glasses and eliminated the small sprayer at the top of the machine. They also had added the heat boost, which would shut off the motor whenever the temp was lower and heat the water. What it ended up doing was to shut off, heat up and come on for a minute, until the temp was lowered by the water hitting all the cold dishes again and shut off again. This was very annoying indeed and took what seemed like forever to run a load of dishes. Then of course without the small sprayer at the top, glasses and anything on the top rack had particles all over them. The longest cycle with heat boost was about 3 hours, which is about what is normal for these days. But at the time I was very disappointed, having spent considerable to buy what I thought & had heard was the very best dishwasher I could at the time. It pretty well soured me on Kitchenaid dishwashers. I did replace it within the year with a reverse rack Maytag dishwasher that I liked very much. It was the all push button one with rapid advance timer. I had that one the longest of any dishwasher and replaced it with a Maytag made Jennaire, which was one of the best machines I ever had. It was before they had two full size spray arms under each rack and had the shower tower non reverse racks. That machine was the easiest to load of any machine I ever had. I could fit all kinds of odd pieces in it and everything came out clean. Now days, all those brands are Whirlpool owned and the dishwasher I have now is a Whirlpool built one for Kenmore. The spray arm on the bottom interchanges with a new Kitchenaid one, so pretty much the same. Good machine for cleaning, but you have to be careful how you load it to get everything clean. I think that is probably because the spray is not as powerful as older machines because they are trying to make it run as quietly as possible.