Thanks!

Re: the breathing discussion, I'm a 'left breather' as well. Recently I've been trying to breath bilaterally and have been having moderate success (however when I feel the need to breath really deep or rest, I tend to lapse back into left-only breathing).

Last night with the 300s (the longest nonstop distance I've swam in some time) I did the first 300 just left-breathing and found that my left obliques in my back got very tight from the rotation and breathing always on the same side. I started doing every 3rd stroke and while I had to focus a bit more to do it, it became natural after a few laps and my back didn't get as sore.