Hi, I haven't tried power yoga, but I do practice Bikram yoga - which is a pretty hard core form of yoga.
For me it was NOT good for weight loss, but it was good for reducing inches and getting STRONG and more flexible. As I have flexibility problems this was one of my main aims anyway. I was going every day for a while and when I was I had abs of steel. Really. It was also good for my 'grit'. When I ran my first 5k and I mean first EVER, it took me quite a while and I wasn't sure I could make it. But I kept telling myself if I could get through 30 consecutive 90 minute Bikram classes where your heart is POUNDING out of your chest and sweat is pouring off you, then I could get thru the 5k.
I have started going back, but only once a week now. I'm glad to be back.
Lose 25lbs by 15 April (10 Mar)
Get to 100 kg (220) by 1 May (7 Apr)
Be 205 by race day - 14 July
One-derland by 1 Sept