My main point against HIT is that is too dangerous. Of course the study you posted backs my "hate" for this training system, but even if it talked wonders about HIT, I wouldn't try it for safety reasons.
The other factor I feel those slighting HIT are missing is the intensity techniques of pre-exhaust, rest-pause and negatives which are used periodically (periodization) to take the target muscle to complete failure.
Exercise selection also meant indirect stimulus had muscles being worked more frequently than it might appear on a the surface. Eg. Reverse grip pulldowns used on both back and bicep day with a pre-exhaust used for back day to weaken the lats before using the fresh biceps to help take them to complete exhaustion.
Basically my point is HIT done in the purist fashion is safe and the volume although one set per body part has intensity techniques to take the muscle to the point absolute failure.
This study showed that anymore than three sets showed no increased results so if anything it supports the lower volume camps. The study did only show that one set to positive failure (unspecified lifting cadence or technique) was not as productive as three sets.
I would also like to know what they consider an experienced lifter, their is plenty of experience in my gym, not necessarily freak size. This study supports only 3 sets per body part over a 14 week period, I would not call that a large time frame.
Good study however if read correctly it will prevent a lot of noobs doing twenty set bicep routines trying to copy Arnold.