Re: How is sailing on large bodies of water?
I think that the satisfaction one receives from any activity in life largely depends on the expectations associated with that activity. Certainly, racing is very close to what you describe - a long downwind run followed by tacking back to windward. But the excitement of competition and the learning can be outstanding.
Growing up, my dad had a Catalina 22, 27 and finally 30 that we daysailed out of Ocean City, NJ. We'd head into the ocean on weekend mornings and sail a few miles offshore or along the coast. After years of daysailing, I grew incredibly bored even though the sailing was excellent. So I augmented the daysailing with racing on other boats and cajoled my dada into some long cruises outside NJ. Today, I mix cruising with light racing and that keeps it fresh for me. The short of it is that anything can be boring depending on one's outlook.
It sounds as if a) you've outgrown your environment, b) grown bored with the whole sailing thing, or c) need to look at your current situation for new ways to freshen it.
Sabre 38 "Victoria"