I have never taken a class but I do incorporate many of the stretches from Yoga in my stretching regimen.  Being older, I need every advantage I can get.  I like the Yoga pose/stretches that work the hip joint and hip flexors.  This really makes my training much more comfortable. 

I'm actually a Bikram Yoga drop-out.

 I gave it a shot but it bored me to death! 

Our room was heated to 105-106 degress F.  Class was 90 minutes.  And we went over the 26 postures 2-3 times 

As a beginner I was told not to do the full stretches until several classes into the program ... although I found them not that difficult.  What I did find difficult was holding certain postures while dripping wet!  I also noticed that in the last 15 min of the class I was getting dizzy & nauseous... whether it was the the heat or the back bends that did it , I am not sure.

I tell you though, I never drank so much water in my life!  I drank nearly 3 litres the day of the class! 

But for me ... boring.  I can't stay quiet for a whole 90 minutes with sweat dripping out of every conceivable pore in my body! 

Yoga classes with higher temps are great for you as they help your muscles to losen up which leads to greater flexibliity.

I am a huge support of yoga as part of regular training.  Expecially for tall people like myself with the flexibility of a old oak tree.