I sounds like an issue that varies between stores.

A few years ago I took my MBP to the reseller I bought it from due to an issue with the fans. They told me it wasn’t the fans but the hard drive, so they replaced the hard drive as it was still under warranty. It didn’t fix the fan problem though which I ended up doing myself.

A few years later I needed to replace the battery. I went to the Meadowhall Apple Store to buy a replacement. I was initially told it would take a few days, so I asked if it could possibly done any quicker. The genius went away and came back to say as it was quiet he could do it now and to come back in an hour. It was all done perfectly.

I’d expect Apple to be more consistent, but it does seem like the member of staff and the store still make a difference.