I think spaces is fine if you're utilizing different desktops for different types of apps, such as media on one screen, disk utilities on another, office work on the next etc.. I do this with Linux. But I have to be honest, I think the point is kind of silly in that you absolutely can not work with 6 different apps all at once, so the idea of needing them all up front at once is really redundant. Therefore, there's nothing wrong with the ol' minimize button, and doing a good ol' alt+tab to get to the app you need, or simply clicking on the app in the taskbar.
Personally speaking, I hate keeping more apps than necessary, open, on any desktop. I like screen real estate/space. But that's just me. I also do this in order to preserve system resources. Again, that's just me.
