Opus is a bit slower at copying than certain tools because as well as copying the file data it also copies file attributes and timestamps. You can turn some of that off in Preferences if you don't care about such things, but most of the time it makes sense to copy them and take a slight speed hit.
If you want less memory usage, turn off all your background images and minimize the number of icons etc. you use/display. That said, I have a lot of backgrounds and icons etc. in Opus and it's using about 12meg, rather than 20-30.
Keep in mind that Windows will page unused memory out to disk so it only matters if all of this memory is in constant use.
[quote]-why can i select files on Details Mode and other views like in Power
Mode (full-row selection, left button:auto-deselect, right button:normal drag select etc)[/quote]
There's an option for full-row-select in Details Mode but if you want to change what the mouse buttons do then you should use Power Mode. That is exactly what Power Mode exists for, while Details Mode is aimed at being (generally) compatible with Explorer and Windows as a whole.
Tried the pop-out navigation buttons? They'll make a button appear if you put the mouse in the top-left of the file list, where ".." would appear (but without having to scroll to the top of long lists).
Or just the Up button on a toolbar?
I don't understand why anyone wants the old-fashioned ".." when there are better ways to do it. To each their own, of course, but I haven't heard any positive arguments about what ".." does better than all the other methods.
Dual-aligned toolbars, and toolbars which are associated with styles or particular directories are both good ideas that I hope we'll see one day.
More packer plugins would be nice, although which ones do people really use? Personally I'd like to see better RAR support before thinks like 7Zip are considered, but the problem is RAR is a completely closed format and you can't even licence the code for it, except the awful unrar.dll which Opus currently uses.
That said I may look at writing some packer plugins one day. I've got a lot to do on my existing plugins first, though. So little time.
For more languages, I think GPSoft are pretty open to giving people the resources to translate Opus, provided they're serious about doing the translation and can do a good job. (And the translation is also for a market where there are actually customers to make it worthwhile.)