I think the 3 day Octopuss card is an excellent deal. For $300HK you get R/T on AE which includes the bus transfer to major hotels. The whole trip from the airport to Conrad on HK island took under 1 hour both ways. The are free luggage carts at the airport and also waiting for you at arrival stations with helpers ready to load/unload your luggage. The bus driver is also very helpful with luggage. Unlimited MRT for full 72 hours after the first MRT use. You also get $20HK credit for use on everything else (Star Ferry, buses, purchases at 7-11, etc.) This also included $50HK deposit, which you get back upon turning the card in at the AE station at the airport. I refilled it only once during my recent 7 day stay for $50HK and it took me everywhere I wanted to go during the week. I did get $42HK back, only because I did go over the limit. The card allows up to $30HK overdraft which is subracted from the deposit. It's a good thing that I did get the $40 back as CX had to charge me extra for some tax upon check-in and guess how much it was? $40HK.
Anyway, the Octopuss card is an excellent product IMHO.

[This message has been edited by andrzej (edited Mar 16, 2004).]