One issue that crops up with rangefinders is focus fishing. Since everything is sharp in the viewfinder it is difficult to know which way to move the lens to focus without a lot of experience. The key is to return the lens to infinity after each photo. You will always know the direction to focus then and it makes the camera much faster to focus. This is especially true with untabbed lenses.
I go back and forth between SLRs and rangefinders. I've been doing it my whole life though so I don't find it all that daunting. Rangefinders are nice since they can be so small, though some SLRs are small too. The one real benefit to rangefinders is seeing outside the frame. With fixed lenses on SLRs you need to move the camera around. I prefer zooms on SLRs for this reason. Another nice thing about rangefinders, at least in the Leica M mount, is choice for lenses.
The Canon 7 is a fantastic camera. I generally prefer using it to my Leica M3, though I usually use my Konica Hexar RF since I like the automation.