The 710 and 810 were impressive units but the book is quite right about their operation. Their automatic mechanism was so complicated and difficult to set up it was a fine line between the auto-trip not operating at all and operating far too soon in the middle of the record!
I restored one once and was quite impressed by its performance when I finally got it running after an entire weekend of tweaking (and swearing...) - it was very different to the rest of the shoddy tat (IMHO of course!) that BSR churned out.
After this, I did what my dad told me to when I first developed my obsession with turntables at the age of about 10, and stuck to Garrards!