I have 2 jobs. A salaried position in a 500 person company, and a 4 person consulting company. At my day job, I work about 15-20 hours/week for 9 months out of the year. If I were to work more, the company couldn't keep up with my work product. The other 3 months I work 30-45 hours per week. This is a full time salaried position.
In my consulting business I have 1 long term contract that requires 5-10 hour per week except twice per year when I have to travel. Small jobs come in sporadically, and I figure $2k/day when doing the bid proposals, and most the time I get it done in a fraction of the estimated time. Since we bill for the deliverable and not based on time, any efficiency gains are my benefit, not the clients. I have had a few miraculous gigs where I've made more than 2 stacks of high society in a single day.
I'm pretty lucky. My field is very inefficient, and people qualified to do the work are not great technology users. Since I'm a capable programmer, I automate many parts of my job and reap the benefits. My company does as well, since the tools I build allow us to have fewer PhDs to support the number of contracts we have than most of our competition.
I have great work/life balance and a high income by most standards.