init7's post about overbooking is somewhat misleading. As their customer, I think it's more about how overbooking hurts them as a provider, not just us end-users.

I used to have a 10Gbps connection through Swisscom (Switzerland's de-facto main fiber provider) using XGS-PON. My internet service was from a third-party ISP, but the underlying infrastructure was Swisscom's. My speed tests consistently showed around 8Gbps up and down (10G minus XGS-PON overhead)

Init7's issue is that XGS-PON requires specific equipment and network access from Swisscom. Swisscom charges them for this, and it can also create other limitations (I remember problems with IPv6). With P2P fiber, init7 can connect directly to their own equipment in a local hub, giving them more control.

For most users, the occasional latency spikes or brief speed drops from 8Gbps to 1Gbps aren't a major concern - at least I never had serious problem with FPS games where latency matters.