Sincerely i don't use video recording with my v3, a waste rite?
If i am not wrong, Ixus S400 has higher MP.
Ixus S400 - 4MP, 3x optical zoom
Movie images : Large: 320 x 240 (3 min)
Small: 160 x 120 (3 min)
Ixus V3 - 3.2MP, 2x optical zoom
Movie Images Large: 640 x 480 pixels
Medium:320 x 240 pixels
Small: 160 x 120 pixels
Ixus V2 - 2MP, 2x optical zoom
Movie Images Large: 640 x 480 pixels
Medium:320 x 240 pixels
Small: 160 x 120 pixels
As for Ixus 330, it is totally out of the market.
So kinda difficult for me to get the specs.
As u could note, for movies recording, V2 and V3 has larger movie images than the latest released S400. This is the only shortcomings reported by those S400 users.
(But heck this is a digital camera, not specialised camcorder.
)
So hor, depends on what MP u wan and the optical zoom.
Price does differ, if you just want to print on 4R photos and only on rare occassions u need to print the images @ larger sizes, a V2 is suffice. Of course, get V3 for the 1MP difference, is also good.
In 4R prints, if u dun check very carefully, pictures taken by V2 and V3 doesn't differ much. But the differences will be acute if u enlarge the prints.
Anyway, it all depends on ur budget and ur requirements.
Buy what u need and what u could afford.