Trying to Get My #$%@# SPL Count Down

I was noticing that it took me about 22 pulls to get accross our 25 yard pool. I am a big guy with long arms, so I realized that this is rather high. (was I right?) So I decided to work on getting it lower. I took some tips from my coach regarding my stroke (my arms were crossing over a bit and I needed to roll more). I also did some 25 yard drills where I simply concentrated on nothing more than getting across the pool in as few strokes as possible. I'm to the point where if I do a good push off glide after a short rest and really concentrate I can make it in 17 or 18 strokes (is that still really bad?). But out of a flip turn my SPL is still over 20. Sometimes as high as 23. (Are my flip turns the real problem?) Now I'm going to pose something that flies in the face of conventional wisdom to the point of swimming blaspemy. In cycling one tries to maintain an optimum cadence for maximum effiency. In general, you shoot for the highest cadence where you are not bouncing in your seat. Mashing in really high gears is discouraged. Sure, you get really good speed initially, but riding the big gears will wear a rider out more quickly than spinning the smaller gears. Why doesn't this apply to swimming? Especially long distance or open water swimmers? When I get across the pool in 19 strokes or less, my arms feel like my legs do when I've been riding big gears at a lower speed. In other words, I seem to get tapped out faster when I'm working to get my stroke count down. The bottom line is that I train soley for open water and triathlon events. Should I worry as much about my SPL as a someone who trains for pool events?