I agree with fat rat. There are way too many factors to figure in to come up with a definite answer for everyone. You have to figure it out on your own.
Some more food for thought that I thought I would throw in.
Casuallbb's study doesnt mention the intensity or volume that the participants trained at.
With training to failure, you are maximizing the amount of growth, but also maximizing the recovery time. There is a threashold that you will come to when your workout wont stimulate anymore growth, but can keep lengthening your recovery time. Its a delicate balance if you really want to maximize. There is no definite line for everyone. It depends way too much on diet, genetics, amount and quality of sleep, metabolizm and so on.
One thing I notice everyone mentioning is the # of times you can grow. The thing I dont see anyone mentioning is the size of growth per workout. I myself find it hard to believe that you can grow as much from 1 DC workout as you can from a 1/week workout. But the catch is in the recovery time. If I grow 1/32" from 1 DC workout, and grow 1/16" from a 1/week workout then it would be worth it to volume train, but if my body reacts to DC by growing 3/64, and 1/week by growing 1/16, then DC is worth it because in 1 year. I would have grown 3 1/4" from volume, and 4 1/4" from DC.
I personally have been doing a 1/week workout, crawling out of the gym every workout, but am going to give DC a shot here in a few weeks.
I havent done measurements, but I have gained 16 lbs since I started working out about 3 months ago. My diet needs work, but I am happy with my gains so far. Maybe I can grow more on DC though. Its worth a shot.