FRITZBoxes

Is anyone using a FRITZBox with BT FTTP?
Is anyone using a FRITZBox 7530AX with BT FTTP?

I am have used a 7590 and I am now using a 4060AX on a OR FTTP line (Aquiss not BT). On FTTP, the 7590’s modem is a redundant piece of hardware. FWiW, the 4060AX is a great piece of kit well suited to my 350/50 FTTP connection. It is also cheaper than the 7590AX. I got mine from Germany in two days for just over £200 all taxes paid.

using a 7530 - not AX with Openreach to Zen. If that's any use.

You probably already realise this, but just in case: if you take service from BT but don't use their supplied router, you'll lose access to voice calls.

It's all locked down. You cannot use the ATA and DECT telephony features of the FRITZBox 7530AX with it.

But you are of course free to use an voip service provider you want.

As a router for FTTP access? Will be fine.

Re for voice…as noted; ‘not clear in your OP if your intention is to take the Digital Voice service from BT (residential/consumer) in which case you must use their SmartHub to access this service.

On the other hand you are free to use any one or more third party VOIP service “over the top” of their actual FTTP broadband service and use whatever (compatible) equipment (including Fritzboxes) you wish as the VoIP client in this case.

Depends what you want.