Ryan, RPTVs generally need about 100 hours of operation to "settle in".
I'd recommend you get a copy of the Avia Guide to Home Theater dvd. This is a calibration disc that has test patterns and a set of color filters included to help you set up the tv's video settings. It might be hard to find locally but can be ordered from Amazon or DVD Empire.
You can use this or just the THX optimizer feature on many dvds to set up your set right away. These only involve the user controls and aren't permanent changes, so they can be redone periodically as necessary during the break in period.
An ISF calibration in which a professional makes permanent adjustments in the service menu as well as possibly some physical adjustments of focus and such should not be done until the set's broken in.
The cable TV signal looks like crap - fuzzy and washed out. I know that RPTVs aren't great for cable viewing, but what performance should be expected? I've tried to tinker with the video settings, but to no avail.
RPTVs magnify any poor cable pic faults a great deal. Feed a mediocre cable signal to an HD ready set and the line doubling makes it worse.
My HD ready rptv looks pretty crappy on some of my analog cable channels but quite good on others.
Your Mits should look pretty good if you feed it a good signal. Maybe call your cable company and see if they can get you a better signal quality.
In the meantime, turn your sharpness way down to reduce graininess.
"washed out" usually means blacks are more grayish than black, try turning down the brightness control.
Basically you want to get a good black and white picture to start with.
Do the following in a fairly dim room, not completely dark but not brightly lit. Turn off SVM, auto color, and put the tv in Cinema or Movie or similar picture mode.
Turn your color all the way down so the picture is black and white.
Set contrast down until whites turn gray, then back up until they just turn white but no higher.
Turn brightness up until blacks turn gray, then back down until they are true black and you start to lose detail in very dark scenes. It's normal to not be able to see all the details in very dark scenes. If you turn brightness up enough to see all the dark detail you will have a washed out picture.
Next turn color way up until faces start to flouresce a bit.
Now adjust tint or hue to get the most realistic fleshtones with the color turned up too far.
Finally turn color back down until fleshtones look natural, not sunburned or glowing. This can often be way below the factory setting.
Again double check sharpness and turn it down to 25% or less.
If you sometimes need to watch in a more brightly lit room, store a higher contrast setting under a different picture mode than your preliminary settings.