I have been on this routine for about 18 months. Waking up early in the morning is not easy or fun, but the alternative is to work in the evening or not at all. I find working in the evening really difficult because after a full day of work and a nice dinner with my wife - I am not really in the mood to "go back to work". Waking up early allows me to put my personal project into a set routine. 2 hours every day - not 2.5 or 3 or an all-nighter. This constraint is great for focusing the mind and making those 2 hours really productive.

There is one downside. I really need to be asleep by 9:30 (I actually wake up at 4:30). This is difficult to do when I meet up with friends. For example, this week I have two meetups planned - both of which will probably cause me to get home past 10:30 which means I am more likely lie in the next morning. ...and I agree with the OP - it is much easier to keep a schedule like this if you do it every day.