The 33 is confusing. It costs 5.50 per person if booked in advance (and assuming there are Advance Purchase Singles available for that day). I am going in April and have bought ten of them (for a total of 55) as I will be in and out of London/England for the following two weeks and will base at an airport hotel. Moreover is the price not 25 per person for singles (i.e. 50 for the HEX alone) that are not discounted? That would make the Uber option even more attractive.

If the discounted singles are available that day Option one is half of Ub er and more appealing unless you have mobility issues or unwieldy luggage. If there are no discounted singles available option 2 wins hands down.