I really enjoy holding a print in my hands; it's a very intimate experience that I value dearly. You can feel the texture and weight of the paper in your very hands.
At the same time I view a print that's mounted behind a window mat as more 'complete', and it's easier for me to step back from scrutinizing the details and focus on the bigger picture (literally). When I finish a series of prints, I try to have them all mounted and put behind a window mat, because it sort of seals the project and allows me to break free and move on to the next one.
Strangely, though, I don't like viewing prints when they're framed on the wall and behind glass anymore. I still display some of my work and other people's work on my walls this way, mainly because it's the only practical way with dust flying around and cats acting upon their curiosity 'can't help myself but I gotta scratch it' drive.
I guess I love it all, but how the picture is displayed alters how I view the it, with most certainty.