I think waking up used to be a chore but now it doesn't seem to be a problem at all. I'm probably pretty weird in that stick to a pretty strict bedtime of around 0900pm. I think because I stick to around that time it makes it pretty easy for me to fall asleep and stay asleep. Alarm is currently set to 0500 but many times I'm awake before my alarm.
Personally I like to workout early in the morning around 5am because there's a lot less people at the gym so it makes it easier to move through my workout more quickly and there's less distractions as well.
Anyhow.. when I first started working out a couple years ago I used to stick to around 30 minute workouts because I was just getting going with working out and because it was a difficult enough goal to just do what I was doing. Lately I'm working towards longer workouts.