1.) I started a morning practice after about two years of 3 to 6 days evening practice, typical led/flow/asthanga-based classes. I remember the first few months of practice - I couldn't sit cross-legged on the floor without falling over backwards. Seated forward folds required a strap around my feet. Utthita Hasta Padangusthasana required a strap for a long time. Sirsasana freaked me out. Handstands were even worse. But I practiced many times a week for two years and loosened up.
2.) 7am wasn't that big a shift. I learned that my body could indeed handle full Primary five to six days a week, and that I shouldn't have been as intimidated by Tim's studio as I had been. That was almost exactly a year ago.
3.) I then finished grad school and got a real job. I started July 5th, 2011. Inspired by a few others who show up at Tim's at 6am to practice while others are busy in pranayam, I decided to adopt an 8:30pm bedtime and practice from 6 to 8ish, so I could get to work by 8:20 or 8:30. This was hard. One issue was that an hour made a big difference in how early I had to go to bed, how well I could sleep. The other, primary, issue, was that at 6am I was stiff like concrete. Half lotus-y poses could only be achieved after forty breaths in eka pada rajakapotasana.
Then I realized that practicing Primary M/W/F/S and practicing in the evening via led class on T/Th was killing me - my hips locked up so badly after lotus-free evening practice that the next morning was invariably brutal. At one point I texted a friend after a morning practice: "7x surya A, 7x surya B, and still no paschimottanasana!". That pretty well summed it up. I did, however, learn that I am more naturally gifted at backbending than anything else in Ashtanga (not saying much).
So I tried a different shala on T/Th mornings. Mysore-style, full Primary. Oh, hello, pelvis, nice to speak to you again. It was abundantly clear that I needed to practice full Primary every day. I didn't dig the shala, though, the other participants spent time drinking water, chatting, and checking their phones, and I was the only one putting full effort into the practice. The environment was drawing energy from me.
Work moved to a new office, the new gym space has a section with hardwood floors.
I practice there now Tues/Thurs, despite the clanking of weights in the next room, the 65-70 degree temperatures, the dirty floor, and the mirrors.
But you know what? The solo practice is beautiful too, in its own way.