I think that creating of semi-flexible layouts is perfect. I mean sites that are stretching among 1024-1280 screen-resolutions.
Definitely, flexible layouts are much more demanding, so I think they show some class of HTML-coder. I agree with TheDoc that you have much more control while working with fixed sites, but that is true only from developer’s point of view. When we talk about users, I think, it would be more suitable for them to deal with sites that use higher screen-resolutions area wisely, giving them comfortable line-width of texts and margins.