I've trained at 5am-ish for the last 5 years or so. I loved it. Some people have more energy in the morning - you know, "morning people". I've hit many PR's in the morning, some even on a semi-empty stomach.
I'm actually trying to do more afternoon lifting now. I want to see the main differences. Wondering if having several meals in my system will help me. Wondering if I'll have less energy b/c I'll have spent most of it on work. So far, I like ending the work day by training as opposed to starting it. When I would train at 5am, I'd be in a rush and constantly thinking about everything that I had to do that day. NOt a great mind set for training. Now it's more of a "the day is over, move on" type of mentality. Plus it's a good break before evening's activities.
More people in the gym tho.