I've recently started using the Finis Swimsense with my swims. Except for two "wishes," I love the damn thing.
I've found that I'm a bit more consistent than I thought. Check out these sets. It consisted of a 300 steady, :20 rest, then 2 x 50 fast, :20 rest, repeat. (N.b: In my pool, 9 laps is 301.8 yards, or 275.9 meters. I set the watch at 15m per length, so let's call these main sets 300 yards.)
You can see that my fastest 300 was 4:42, slowest 4:53. Is that considered "steady?" Not sure. That is :11 difference. But the 50s are better, I think. All around :38. (That first 40.2, I think, was from my not hitting the PAUSE button right away.) You can see that the last length of each 50 was a bit slower than the other two lengths (weird to talk about three lengths for a 50, eh?). This is probably because of having to hit the wall, then hit the PAUSE button. In general, though, I am staying pretty steady, especially considering I did the 2 x 50 four times.
This next picture demonstrates the benefits and problems with the watch.
The green reps means I did backstroke. Yes, the watch can tell what stroke you're swimming. But look closely. That 27.1 sec length is actually two lengths. Actually, the 19.4, 11, and 27.1 sec lengths are probably really four lengths.
You see, what happens is: if you do not streamline long enough, the watch won't realize that you've started a new length. This has happened in some of my freestyle sets. (Honestly, the above described 4 x 300, was actually a 5 x 300, but the fourth set had a couple of these double lengths.) Also, look what it does to my pace count. The sixth length being the super-fast :11 length results in a 1:16 per 100m pace for backstroke. Wow! Of course, that speed cost me with the 3:01/100m length!
A few things I wish you could do with the watch that either you can't, or I haven't figured out yet: I'd like to be able to split a long length, like the 27.1 sec one above, into two lengths to make up for my horrible streamlining. Secondly, I'd like to tell the watch I'm drilling, then be able in the computer to type in how many yards I'd swum during the drill. As it stands now, if you're drilling without regular stroking (one-arm, 6/1/6, kicking), the watch will get confused each time your watch-arm streamlines. So, when I upload my 3200 yard workout, it comes up short with however many yards I drilled. And lastly, I wish I could adjust the brightness of the display. It is hard to see the watch, specifically what lap I'm on, underwater. (OK, that's three wishes, not two.)
Why does that matter? Well, in this system you can set goals. And one of my goals is 20 miles in December. Not sure I'll get that due to my losing anywhere from 200-800 yards from the drills, per day.
All in all, though, I love this watch. Well worth the money.