I've never used this before and I'm interested in messing around with it a little bit. But I'm curious, how do you shoot with it? Because what you in your viewfinder is dramatically different than what you're going to see when you put it in the proper aspect ratio on your computer.

I've been messing around with this for a while and it's kind of cool. at first it's hard to frame the shot, but once you do a little trial and error you get used to it. unlike a lot of people i've heard from before, i'm not getting that much quality loss. my only gripe is that when i play it back on my tv there are like little "lines" going down the screen. i dont know if it's from the compression in after fx or what, does anyone know what i'm talking about or how to remove them?

No point in doing anything to the footage until the last minute - you really limit your possibilities by doing a title mix and discarding the top and bottom of the frame. Just shoot full frame, then re-frame it and export as anamorphic (for web use) or letterboxed (for output to tape or DVD) as the last step in your post-production process.