Question - from things I have read, there is a chance that not everyone in the street box may be able to get the new service (read things like only some areas serviced by the box get the new service) but am guessing that is for engineering reasons. Can anyone explain more? I hope my box should serve all as it is between 2 estates that are 8 or so years old.
With one exception (*), everyone served by a street box (ie a cabinet, or PCP) will be able to get FTTC service.
The problem is the other way around: some postcodes are served by 2 different cabinets. Where 1 cabinet is upgraded, but the other is not, then a postcode ends up being partially served.
However, any one property is (almost without question) served by 1 cabinet - and so either will or won't get the service.
(*) The one exception is (similar to ADSL) the distance the property is from the cabinet (where in ADSL it is the distance from the exchange). The absolute maximum distance isn't known, and depends on whether the line is made of copper or aluminium). Some places seem to run out of service at 1200 metres, while others are around 1600 metres. I think the longest I've heard of is 1900 metres.