Great kit, I have it and those pics took me far.

That practice core is a pain I thought. If you put anything other than straight pins in it it just binds up. I found sprung core locks easier to learn tension on. I have picked unsprung core commercial locks that were easier than that practice core.

The master 150 is much better for learning counter rotation I think. That is still my favorite to pick and I use it as a warmup lock before working on locks I find challenging.