Unclemo, if you saw a blurry screen on a TW56X81 it was either due to (a) weak cable and/or (b) it wasn't calibrated correctly or recently.
I had to put a Radio Shack cable booster (approx. $24) on my cable wire and then my picture was crystal clear (digital cable won't be in my area for another few weeks). You have to be careful, though, with those boosters because you can overjuice.
Calibration needs to be done initially upon installation and then again after 30 days (you can calibrate it yourself), and then thereafter every 6 months.
With my set you can see the picture clearly even at a 35 degree angle.
As for plasma sets, they'll give you the same problems if you have weak cable. Their calibrations are totally different from my set, so I can't comment on that. Plasma sets are *very* good sets, but very expensive to buy and to fix.
Lori