i have a lot of pictures, but i spend 99% of my time using a quick image viewer (freeware irfanview), rather than inside one of the image browsing apps like acdsee.
now i know that acdsee has an image viewer, but im more interested in having a really super fast and convenient image viewer that shows images when i double click them from windows explorer.
I understand and agree, but ACDSee 7.0 is very quick when opening individual images. That was one of my requirements before settling on it. And it's read-ahead and cache-behind makes browsing images one-by-one very fast, too.
I almost feel like I need to step back and say something like "I'm not a salesman for ACDSee." In fact, I don't like the company much. They recently told me that one of the bugs I reported was confirmed, but wouldn't get fixed until the next major release--which means I'll have to pay for a bug fix. Typical nonsense. (Off topic maybe, but typical.)
But anyway, I still don't think there is a distinction to be made. If an image viewer sucks for handling multiple files, it has a lousy feature set. If another application can handle multiple files well, but is slow, then it's a pig. Both should be rated down. ACDSee 5.0 was slower than 7.0, so it sucked. I didn't use version 6.0, but I have read many times that it sucked, too. But 7.0 is the best of both worlds from what I see here... And it's not alone. XnView was pretty good, too.
I'll shutup after this, really... I just don't think it's too much to ask for an image viewer to be both fast and multi-file capable. To me, that's a bare minimum, and everything else is just a nicety. For example, I wouldn't put image-editing or screen-capture features in with those two criteria. I don't consider those things to be essentials for an image viewer.
It has got to be fast, and it has to be able to handle lots of files. If not, it's shitware. (I'm such a binary bastard!)