I have been with AAISP for over twenty years. Excellent customer service and technical support (that isn't script driven). You get what you pay for.
My most recent experience was with a switch from FTTC to FTTP.
They set up the FTTP on the same account I have for FTTC. They sent me a router and set up a temporary IP address to use. Once OpenReach had installed the fibre, I was able to test it. The next day, I called and had a very short interaction with technical support, where they switched the FTTP and FTTC with each other, so that my public IP addresses were correctly routed to the FTTP.
The following day, all being OK, I ceased the FTTC account which had been running in parallel. I was charged just two days' overlap, unlike the full month required by some others.
They are a joy to use.
Time With Provider: 20 Years
Package Name: SoHo::1