I just got xnview, and it seems very usable to me.
I mostly need it to fully replace the built in Windows7 Photo-viewer, which is bugging me with constantly opening new windows of itself every time you double-click an image-file since day one.
However I have gotten pretty used to the zooming behavior of the Photo-viewer.
It Zooms with the Mouse-wheel (almost) infinite to where the Cursor is and it drags the picture with the left mouse.
In xnview I can drag the picture with the left mouse button, but when the picture reaches its native resolution, the mouse wheel turns from zooming to scrolling around, which is bad.
So how can I adjust this to my needs?