Anyone use one? Thoughts on if it is an improvement, which brands and models are good?

I tried a Panamax DBS 500. I didn't notice any difference in sound from the power filters, however when I ran my antenna connection through it its rf section the signal was significantly degraded. I would not spend money on line conditioning without seeing some real scientific evidence in support of a particular solution. Not unless I had a specific problem and then I would look first to the service wiring before looking at a secondary solution.

I am having a problem with degraded signal on my TV set in my bedroom(a decent 27 inch Zenith).

Any one think a line amp will help? I'd like to get rid of the lower quality signal. I hooked my old 19 inch Magnovox to it, and the picture was much cleaner.

Video inputs on the TV come through fine.

I'd check the cable your using to make the connection as well as the input on your television. I have an antenna amplifier if that's what you mean by a line amp. It does a great job of improving reception for our rural off air reception. It could be that the tuner in your set is not very good. I'm guessing you are running through a vcr and its tuner when you say you are using the video input. My toshiba vcr tuner seems somewhat better than my toshiba tv tuner.

A line drop amp does work very well. It works like the signal booster above but also does have filtering.
I use the 2400 model.
http://www.electroline.com/en/products/drop_amplifiers/eda/index.html

I use a line conditioner because I have sometimes power fluctuations in this older apartment building. Giving steady full power to any power source keeps that power source healthy. The fluctuations is what kills em .. such high failure rates with power supplies in computers.

This is what I got:
http://www.tripplite.com/products/product.cfm?productID=211
It does not improve sound...myth...but it does keep my power steady and clean.

I have used a bunch of different brands in the past, but now I use 2 Monster AVS2000's, and 1 HTS5100. The AVS2000 was where there was a significant improvement in sound, not so much in detail, but more in openess, more depth. It was like the amps were able to finally breath. Giving your theater the power it needs is essential, and the AVS2000 will do this proper.The 5100 I use for my source components, RPTV, and Preamp (not with the amps since it chokes the power a bit) with very little difference in pic quality. It's mostly there for piece of mind. I'm not sure what your budget is, but I would suggest going with a line conditioner first, and later on getting a voltage stabilizer if you live in an area where your power dips low.