Most "research" that you will find on HIT, especially on the internet, is extremely biased towards this method of training. Advocates of this method pretty much dismiss all other philosophies, believing they have found the end all of training. This, of course, is wrong as there is absolutely no best way to train. Even periodization has its flaws.
There was, and to some extent still is, intense debate in the Exercise Science community about the number of sets required for "optimal" adaptation to occur. Many studies have been done on this, and most of them showed one set training to failure to be just as effective as multiple sets. However, the biggest flaw in most of these studies, and this is a huge flaw, is that most of the participants were UNTRAINED subjects. While HIT advocates will be quick to point out such research, it is practically as worthless as the paper it is written on unless one is training previously sedentary people. They certainly need to review the concept of external validity further. Indeed, this is just one of the many flaws inherent in most of this research.
As we know, with beginners (or untrained subjects), practically any method of training will work. It doesn't matter what the hell you do with a beginner, they will certainly get bigger and stronger as a result of resistance training. Just think about when you started training, you probably didn't know what you were doing, probably overtrained like hell, but still put on 20lbs in a year without any steroid use. HIT is probably as effective as multiple sets with beginners, but for more advanced trainees I, and the vast multitude of top lifters, do not believe it to be superior. It is fine for training Couchpotato Charlie, but not for Mighty Mike who has been lifting for 10 years.
In your case, though, I assume you are not a previously untrained subject. As a result, your body needs more volume (reps) in order to grow, amongst other things than does a novice. One set is just not enough for someone who has lifted for a while I don't care how focused or intense that set is. Go ask Louie Simmons, Shane Hamman, or any other elite lifter if they ever train with one set and you will certainly get a "no" for an answer. Maybe some guys like Dorian Yates can get away with such training, but I will stay with the methods that have produced thousands of top lifters for the last 50 years.
In the end, though, the true test is whether or not it works for you. I tried HIT and, like many others, found it to be inferior to multiple sets. My advice would be for you to try it for a while, and judge it for yourself. If it doesn't work, it isn't like the 6 or 8 weeks you spend doing it will dramatically affect your long-term strength and size levels, and it will at the least give you a break from what you have been doing. I find it folly that many people will criticize HIT without even trying it, so give it a shot and then you will be able to give your own opinion as to its efficacy. I will post more on this at another time (prob. tomorrow), as I have a lot to say but it is very late.