FTTC then VDSL to the room?

Just learned about FTTC in wikipedia. And just wonder if my house distance is far from the FTTCabine, the speed of VDSL connection from the cabine to my house will be slower compare with people's house if closer to the cabine?

Is this why with BT infinity people might get 13Mbit down and 6 Mbit up speed, where others get 38 Mbit and 10 mbit?

Yes, the speed of VDSL2 varies with distance, just like any DSL technology.

BT uses profile 8C, with frequencies up to 7MHz, and sets a maximum (at the moment) of 40Mbps down and 10Mbps up. This maximum is available within around 400-600 metres from the cabinet, and then steadily falls off over the next 1000 metres or so.

They are due to start using profile 17A, with frequencies up to 17MHz, sometime over the next year or so. BT think that this will double speeds (for those closest to the cabinet), but will also increase the range.