Originally Posted by
mtkeller
HEC is the cheaper of the "fast" options, but checking the timetable, it looks like you barely gain any time by the time you factor in getting to Paddington. HEX is better in that regard, but more expensive.
Though, note that the HEC runs less often, and on one recent weekend (sorry, I can't remember details, it might have been a Sunday in March) the HEC was only running once per hour. If you miss it, you've lost tube time or are stuck with a hefty HEX fare.
I'd honestly take the Underground, so long as you've got a clear shot to the Piccadilly line without engineering work getting in the way.
I've had at least one amusing experience with the tube acting like a deranged drunk on an early weekend morning. I tried to catch the first Circle Line train of the day, and it was not marked with any destination or line designation. It sort of went to whatever stations it felt like (one of which was on the District Line, not the Circle Line) and stopped for unexplained delays. I was glad to be off the thing, finally at Paddington, but not quite at the time I had intended. Take patience along with you.