I think its really important that it's explained why the HIIT model you used works. You are describing the model used by Wisloff et al 2007 which has found huge increases in VO2max (+46%) compared to many other studies. This is irrespective of the population involved (CHF patients) and no one has thus far managed to replicate these massive improvements.

I find it a little odd that you "would recommend this training to anyone" without qualifying why. It doesn't paint us Sport and Exercise Science students in a good light (we is propa sighentists too!). While we justify the effectiveness of a HIIT programme by its effect on VO2max it doesn't always give a clear picture of what else is going on. The duration and intensity of intervals plays a big role. For example Stepto et al 1999 highlights that training with either long intervals of around 4 minutes and All-out sprint intervals for 30 seconds with 4-4 1/2 minutes recovery have similar effects upon measures of aerobic performance (e.g. 40 km time trial performance). Most other interval durations are less effective. What is most interesting is that the mechanisms which cause these improvements are different. Longer intervals seem to be better for improving the structural properties of the cardiovascular system (mainly the heart) improving the supply of oxygen to the muscles whereas sprint interval training has more metabolic effects at the muscle level which improves the ability of the muscles to work aerobically.

Update on the way. HIIT me with questions in the meantime.