I changed docs just a couple of months ago.
The main issue was that there is a shortage of docs in the area, so when I contacted my surgery of choice (closest, easiest access, one of the biggest in the area, with enough docs that I will have a choice if I end up wanting to avoid an individual dinosaur) I was told they would put me 'on the waiting list and contact me when there was a vacancy'.
I interpreted this as having to wait for a patient to die (sobering thought) or for someone to leave the area or move as I wanted to move, to another surgery.
Anyway, I had to wait about 4 months, then out of the blue got a call saying that I had reached the head of the queue, and could I please come in within 7 days to register.
Re your prescription issues:
My old surgery - electronic repeats possible, frequent reviews which required an appointment with nurse or doc, a hassley rigmarole of obvious reluctance in complying with my endocrinologist's instructions for prescriptions. Had to go to surgery to pick up prescription.
My new surgery - electronic repeats possible, automatically delivered to the pharmacy of my choice, so I only have to go out and pick up the drugs, prescription reviews confirmed as annual, done over the phone by resident pharmacist.
I am a happy bunny.