I used to use Gatwick a lot, but always travelled on GatEx with an ordinary ticket, including Network Awaybreaks when they still existed. This was because I was going right through London, so I believe it was perfectly valid. Thameslink was a valid option, but that would have involved an awkward climb out of KXT with heavy luggage. StP is an altogether better option.
Really, GatEx can no longer justify premium fares. There is no special infrastructure and no real advantage other than having more luggage space. There might be an argument for it if they wanted to keep non-airport passengers away from it, but that does not really apply, since there is no real speed advantage.
I was careful not to call HEX a "franchise". It must be a waste of resources having a separate organisation for such a small number of trains though
I agree with that. All we are really paying for is use of the dedicated tunnel. That tunnel is a cash cow for BAA, which is probably why there is not a dedicated light rail/bus link from West Drayton (which would allow main line expresses to stop there). I don't know about maintenance and operating costs (which must be high) but it surely cannot justify a fare of £9:50 per passenger to use it (standard on HC, just from Hayes). Really, the government should buy the tunnel, sell it to Network Rail and merge HEX with FGW or its successor. They could sweeten that by offering to pay for a light rail link under the M25 to West Drayton (or Heathrow Airport Parkway if they prefer). HEX fares would then go into the standard ATOC fare structure and drop to normal economic levels. This should really happen before Crossrail gets going - i.e.
right now.