I have connected with a corded phone but the line sounds clean and I have had no problems with calls.
The new router has been stable with a sync speed of 32Mb/s and I have had no issues with disconnecteds. The speed is a bit less that it used to be, but the connection is OK.
I have just discovered that Opeanreach has been insalling new telephone poles in the street over the last month or so. My connection has not been replaced but it may be related.