Originally Posted by
WorldLux
I find the journey planner useless for trips to/from Heathrow as it seems to use HEX by default and there's no option to only exclude HEX (it's either all non TFL trains or nothing).
That is not correct. By default, it includes everything and will almost systematically route via HEX from most Central/East/North London departure points. If you exclude "national rail", it will include tube and tfl rail to Heathrow (née Heathrow Connect) but not HEX and will usually route via tfl rail. If you exclude "national rail" and "tfl rail", it will typically route via the piccadilly line to Heathrow.
That said, in the last year or so, I have seen an increasing number of bizarre suggestions on some tube journeys to various locations including Heathrow, adding unnecessary changes that do not really save any time.