We have owned front loaders for about 1-1/2 years after 40 years with top loaders. My guess is the front loaders use more time to wash and dry but I cannot quantify. The new machines have timer displays that estimate wash/dry time when you start a load and then they count down. But we have noticed, especially with the dryer, that, sometimes, the last part of a load counts down much quicker than the estimate. In other words, the last 15 minutes might only take 8-10 minutes.
We have also noticed that when the dryer stops, it is done. No throwing a towel or sweatshirt back in to finish. Wash and dry quality is better than the older machines - but they were older.
One thing for certain. The top load washer uses less water and combined they use less energy. After two month it was pretty clear that our water and electric bills were lower. There isn't much variance in use because it is wife and I and we are retired.
RonB