That's one of the concerns I have: finding a model with enough flexibility to allow me to correct all the different ways that channels have found to screw up the size and aspect ratio.
There's just no avoiding it when the new screens are 16:9 and the old content is 4:3. They give you options so you can pick what you prefer.
I lean toward "purist". I don't "stretch" old content or try to make it anything it wasn't. Some people like the various stretched modes. I just live with the pillarboxing necessary, which wastes some screen real estate.
Other folks like to do the stretch thing. Or the modified stretch thing where the center is less stretched than the content near the edges. (Not sure on your set, but that's the difference between "wide fit" and "screen fit" I suspect.) I don't like how either one look. Would rather see what the original was intended to look like, myself.
This model has 16:9, 4:3, "wide fit", "screen fit", and "Custom". Haven't figured out yet how to "customize" my picture settings. But obviously if the aspect ratio doesn't match your screen, there will either be clipping, unused screen area, or distortion. So far "screen fit" seems to be a good setting for movies on DVD and "wide fit" or 16:9 works well for HD channels over cable.
Every manufacturer means something different with "custom" so I won't even bother on that one.
Most DVD stuff will be 4:3 but there's also the evil DVDs that were letterboxed to 16:9... Those look awful on a real 16:9 set because you pillarbox to 4:3 and then that is also letterboxed. Ick.
Also I suspect if you check the manual, "wide fit" probably reverts to native 16:9 when you select a true 16:9 source like the cable channels. There's nothing to "fit", so to speak. So it goes to sleep essentially.
Want to get really weird? My satellite box can do Picture in Picture. Overlaid is normal, but it can also do side-by-side. In that mode the whole screen becomes letterboxed, but there's two 16:9 pictures side by side with a small black border line down the center and around the outside. Haha.
Wastes a lot of space, but it's great for watching a football game continuously on one side and Red Zone channel on the other!
You'll find settings you like, and nobody really agrees on what they like. But after a while messing with the setting becomes a novelty except in weird cases where you're watching something oddball that works best with a particular format, and you end up leaving it all in your usual favorite mode.
Have fun playing with it all. Next step, BluRay! Heh.
(Honestly I haven't bothered doing BluRay. We have a small but cherished collection of favorite DVDs that I don't feel like replacing, some of which will never have BluRay replacements anyway.)