One thing, seeing as you are in Scottland, is that Ballnamic accounts for the climate where you tell it you live, so colder weather it will make a different recommendation than someone like me in Florida.cheers, will see if I can pick some a couple from eBay used, just to do some testing, along with trying the ballmanic website.
I have decided when I go back for my next lesson, (hopefully book soon) im gonna take my ST+ with me to use, and see what the pro thinks of my numbers and where im going wrong.