IMO it is best to make 2 or 3 VFAT mods and divide the F-15 flying teams over 2 or 3 days (friday/satuday/sunday). This should give the viewers enough time to switch mods.
The installing and uninstalling of the mods must be very well tested on several systems though, to ensure this it is all bug free (not like the 2006VFAT mod
)
Using 2 servers (West and East) is good to solve possible lag issues but it doesn't change anything about the VFAT mod(s).
Having VFAT twice a year might be a good idea but teams need the time to practise for their next show which obviously takes a long time. Next to that, VFAT will become a less special event if it is taking place more often and shows become less impressive.
Seen the growing amount of teams and their participation it would be best imo to divide VFAT over 2 weekends. Another option is to let each team/solo fly only one time.
Well, VFAT is still quite far away but it's good to start thinking about these issues and to start early with the organization of it (especially pointing at a live stream of the event).
One thing for sure, VFAT2007 will be an even greater event then last year and I really love to see the aerobatic community "forming up" with eachother