Looks like very bad planning to me - they withdraw the direct tube
service but fail to provide a convenient alternative! Surely it
wouldn't be that hard to extend the H25, so that passengers once
again have a convenient service from the rail interchange at
Feltham?

The H25:

* isn't very frequent (4ph weekdays, 2ph evenings and Sundays)
* uses small buses which don't have the extra luggage space of
airport
buses
* isn't very reliable and doesn't often run to timetable
* would provide a worse service on the rest of the route if it was
delayed around Heathrow
* is run by Tellings Golden Millar, the worst bus company in London

I wouldn't imagine BAA would touch it with a barge pole.
Matt Ashby
www.mattashby.com