First of all, thanks everyone for contributing to this chat, which has been invaluable. I'm halfway through my RTW booked through BA. Their service was irritatingly poor last Autumn (when I made my initial flight bookings) and worse when I made a change in November; but now I've come to book the final few flights, and their lack of ability to service my bookings is driving me to despair. I've had five (long) telephone conversations with them this week, each one ending with a promise to process the order, followed by an email the next day asking me to call them (no number given of course), which resulted in them saying "we're not sure why you've been asked to call us but there seems to be a problem". When I ask what, they say that it's been flagged by "the back office team" but I can't talk to them, so they'll ask for me. Then I wait for the next email and on it goes. The latest call suddenly increased the promised response time from "24–48 hours" to "5–7 working days"! I still don't know if I can have my flights, which aren't unusual ones.

I guess the lesson is, if you can't book the whole RTW trip through the online form, or want to make changes, be prepared for a lot of grief if you're dealing with BA.