I can't speak about the competitiveness, since I've been out of that loop for a while. However, I can tell you from my perspective, our group members put in a lot of hours, though family time always takes priority.
The amount of hours you work will always depend upon the type of practice, geographic location, etc. We have a practice that involves a lot of office hours in addition to covering patients in several hospitals, performing consults, surgical procedures in the hospitals, on-call coverage, week-end coverage, etc. But once again, that's dependent on what you create or the type of practice you enter or develop.
I believe it's safe to say that although optometrists and pharmacists may work long hours and/or rotate schedules (especially retail pharmacists), they probably rarely get called for emergencies, don't have to run back and forth to hospitals, perform hospital consults, etc. They are different lines of work with different demands, and your choice should really be based on what interests you the most, because when it's all said and done you should ALWAYS find time for your family. Nothing is more important.