Ten tabling in sets is perfect for me. Early and late play is so brainless that I can watch TV or talk on the phone or do homework or something, only really playing intense poker for maybe 10 minutes each set. If I played continuously, all of my games would be at varying stages, and I would have to have a certain portion of my attention consistently devoted across the span of an hour rather than letting it fluctuating in waves. This works for me because I have a short attention span. Also, I rarely have a solid 3-4 hour block of time that I can devote to poker. I have to squeeze in a set here and there to get my 20 hrs/wk.