Like you, I have experience of two pharmacies.
For my first few diabetes years, I worked near Boots. This was a large city centre store.
At first there were a few IT hiccups but they ironed them out*. The individuals were very good. At one point, they didn't have something in stock but were expecting it that afternoon so delivered it to my office. Another time they didn't have something in stock. the pharmacists recognised my address and realising she walked past my house on the way to work, offered to drop it in.
Since I changed jobs, my nearest pharmacist has been a local (suburban) pharmacist which is part of the Well chain.
I have come to realise what an excellent pharmacist is.
They are located a couple of doors from my GP surgery and are used to mistakes on the prescription. They don't bat an eyelid (although there maybe a little eye rolling) when the GP has prescribed the wrong thing again.
When they didn't have some insulin in stock, they phoned local pharmacists (including competition such as Boots) and reserved some for me.
I now have my flu jab in a relaxed environment at my pharmacy rather than face the surgery melee.
When I was thinking of self funding the Libre, the pharmacist told me they had them on prescription (my DSN had told me they were not available in my area), found out how much he could sell them for and offered to get them in just for me. Unfortunately, they were not one of the cheapest so decided to go for Asda. But no ill-feelings.
I guess the moral of the story is that any pharmacist is as good as the individuals working there regardless of their corporate overlord.
*can you iron out hiccups or am I over mixing my metaphors?