Yep, as mentioned above.
It makes your muscle work harder in a smaller timeframe, which usually leads to less time spent at the gym and, from personal experience, a much harder workout than you regularly would with the standard 3x8, or whatever it may be.
Reason being - and this is my opinion - you are always working out until failure, so you don't give up on the 8th, or put less weight just in order to complete 8. You are always pushing yourself to the max, you are always improving and increasing your overall performance, it's like a "beat your best" every workout. You start with what your last personal best was, or more, and you motivate yourself to do better since you're always working out until failure.
It's a great approach if you ask me, it's been great, cut my gym time a lot shorter and I see much better results, will not be switching out anytmie soon.