So you are definitely on VDSL2 as expected, speed is lower than expected but this can be because a new connection has the DLM (dynamic line management) reset. Speed may improve over the next few days depending on the type of FTTC cabinet you are connected to.
I'm afraid in the case of master sockets the latest isn't the best, the NTE5C is a cheap and nasty thing with a clip on faceplate so I don't expect that to improve your speeds, but you can give it a try.