This wonderful coach service takes you to London cheaply, quickly, and (for a coach) comfortably. And it runs ridiculously frequently; every 12 minutes during the day, and right through the night at reduced frequencies. For those trying to catch the bus in London, the Victoria stop is really at Grosvenor Gardens - this has caused a little confusion. Note also that the coach does not start at Grosvenor Gardens; it starts (and is held until departure time for early boarding) outside the Green Line coach station.
The service is currently (August 2009) transitioning from older to new rolling stock, the older vehicles having covered on the order of a million kilometres in service. The older (Neoplan) coaches have a single staircase and the best seats are found on the upper deck to the rear of this staircase on the kerb-side of the vehicle. The two middle pairs of seats have more legroom than other seats on the bus, though some prefer the downstairs table seats or the very front upper deck seats for reasons of table-space or view whilst en-route.
On the new (Van Hool) coaches, the optimum seats in terms of legroom are the rear kerb-side seats downstairs, which are fitted in the wheelchair space. These have both more legroom and a longer spacing between seats, resulting in a far more comfortable journey. Being set down at floor level they feel far less cramped than any other seats on the vehicle, but the proximity of the toilet may be a negative point worth considering if you are particularly sensitive to the odd smell or two. All other seats on the bus have very restricted recline capability and the overhead console feels low.
Cyclists should also note that on the Van Hool coaches the luggage space has a far more slippery covering and Brompton-riding passengers in particular should take care to make sure their bicycle will not spend the journey careering around the luggage area if possible.
The service's town stops are:
If you plan to catch an evening coach back to Oxford at a busy time (there often seem to be busy spells around 7pm from commuters and around 10-11pm from the post-show crowd) it can be worthwhile catching the coach from the Grosvenor Gardens stop as opposed to Notting Hill Gate or later as this much improves your chances of getting a seat (it's a seats-only service, no standing) over Notting Hill Gate or Shepherds Bush.
For cyclists, when traffic is very congested it can be very worthwhile cycling to Shepherds Bush as you will most likely beat the coach to the stop and gain fifteen minutes or even half an hour versus being stuck in traffic. Similarly, when the traffic is heavy coming into London, get off at Shepherds Bush and cycle rather than waiting for the (slow!) traffic.