For me Personal Recommendation > Qualifications.
Then it's how that person makes me feel. I'm not a confident rider & someone who can boost my confidence is crucial.
I use 2 instructors & both are very well qualified, but it was recommendations that drew me to them initially.
It was such a great place. Just before Dave was broken in, me & my friend used to take turns to drive from Barrow for lessons. She had just lost her horse but wanted to keep the feeling going & I was getting myself ready for Dave! I think it was Gail we used to have a shared lesson with.