The questions of stroke style is a hot topic in the Tri world these days.  Should you swim a distance per stroke style or use a high turnover rate to generate speed?

Consider an approach that utilizes both styles.  DPS or distance per stroke teaches us to take full advantage of each stroke, thereby maximizing effort and achieving a low stroke count.  DPS encourages good strong form and efficiency while getting the most distance out of each stroke.  Drills to improve DPS include catch up and one arm.  Develop your DPS by drills then try this DPS stroke set:  4x50 with 20 second rest between using DPS skills, reduce the number of strokes on each fifty.  Off season and early season is the time to learn good swim form and muscle memory working on your DPS.  Use drills, stroke  improvement sets and pull sets to build a good foundation with distance per stroke.  

Once you have developed your DPS skills then you can speed up the entire process by sharpening high turnover form.  High turnover is similar to a high cadence on the bike.  While keeping strength and form learned by DPS, work on a higher cadence/stroke rate, especially as race season approaches.  A good high turnover stroke set would be:  10x25 at max effort.  Try to get your arms extended as fast as possible, while maintaining proper form.  

A balanced combination of DPS and High stroke rate should lead to better swim times.