I've completed the last 'long swim' in the current block although it'll be a couple of weeks before I go for my next review lesson. Today's pacing was good, both consistent and a little bit more rapid.
There was the usual fatigue but by working hard in the 3rd set it doesn't look too severe. There is some variation in pace as the lanes were a little busy at times and so I was occasionally held up, and occasionally work to accelerate past.
Looking back over the block of 12 weeks there's a distinct improvement in pace although it's uneven and only of the order of 8 seconds/100m from start to finish! Having said that 3.5% gain isn't bad, this article suggests that over 10 weeks an average improvement of 2.5% is reasonable.