I'd hoped to do the third swim of week 10 yesterday but the pool opening hours didn't fit in well with other things I wanted to do. Today I did 4 sets of 66m alternates which went very well. Once again I managed the warm-up at better than 3:00min/100m pace again so this is becoming something I can do reproducibly.
Two lengths were at 2:01min/100m pace including one in the second set so I'm getting slightly faster and able to do fast/slow better too. The first 3 sets had at least 5s per length differential but this dropped to 2s in the last few reps.