I'm comfortable in the water but not particularly fast.
One of my brothers has taken a few swimming classes in hopes of making him a stronger swimmer for various reasons. He too has always been at least comfortable in the water.
The first year they had him working on a total immersion type technique. The following year after the coaches had been to some sort of seminar, they said: "Forget what we told you last year, here's what you should do".
So would any of the Total Immersion books/videos be of use or would I eventually hit a wall in terms of improvement and need to change technique again? Has it fallen from favor?