I think watching and trying to apply what you see to your own stroke is a huge benefit. I was a lifeguard in college and there was a guy who would come in and swim primarily freestyle for long sets and had a a beautiful stroke. I would get in on my break and practice how he was swimming. I think it really made a difference! I still love to watch good swimmers. I actually like to watch bad swimmers too because it shows how crippling certain stroke dynamics can be. Gary Hall Sr. Has some great teaching videos on YouTube and when I am struggling with something in my stroke I go to the videos first. I did have the fastest swim in my A.G. In Kona. Not a huge accomplishment at my age;) The best part is having faster times than a lot of the pros!
Sorry, I gotta draw the line at watching bad swimmers as they are like listening to someone scratching their fingernails across a chalk blackboard. Just can't stand it. :)
Have you heard of the Isoman Triathlon in England??? This race features a 7.0 mile swim, 62.5 mi bike, and 26.2 mi run, e.g. designed to produce roughly equal times in each of the three disciplines if the athlete is equally proficient in all three.
"Anyone can be who they want to be IF they have the HUNGER and the DRIVE."