Rather, as with the 100m repeats, I'll stick at 200m until it becomes trivial, and then double the distance again.
Why do take such large steps? From 100-125-150-175-200 and when it starts to loose comfort, start again with one of your comfort distance...
I would like to do something about my stroke rate. I know it's too slow. But for now, it's not the priority. Next year I will start using a TT.
Well, I'd suggest the FP: No pauses anywhere in your stroke. And if you're satisfied with your seamless stroke, do just a faster recovery (Shinji's hint, so it should not be the worst...) And the use of a TT is not limited to train swimming faster. You may take it to hold your as slow as you like SR constant even in slowest strokes... If very slow you should be proud about your continuous balance. And with 2-3-4 beeps for a single stroke you even will be able to focus on very fine points of your motion. Think you can't start too early using a TT for what you and only you
will achieve in your stroke.