Have done a swimtrek as well and loved it! And I didn't think the rooms were extra small, they were the same size my 'vacation' rooms were after?
With the stroke analysis, what happened to me was that after the stroke/videoing session the guide told me 'your arms are too wide!' and I thought 'duh, doing TI, that's on purpose!'
... but when viewing the underwater video I got that he was talking about arms too wide underwater, and he was right. Still doing skatch drills regularly, hope I've got that under control now.