IMHO, the SONY 50" LCD has a better scaler than the Samsung when viewing standard definition programming. The putting greens had a "posterized" look while watching golf on a friend's brand new 50" Samsung DLP. I saw the same artifact on the demo set at Best Buys yesterday. The Sony doesn't do that.
Considering 98% of what is on TV is standard definition, the quality of the scaler is a very important consideration when watching all those SDTV shows.
Also, the SONY LCD chip has slightly higher resolution than the Samsung (768X1366 for Sony vs 720X1280 for Samsung). Considering they retail for the same price it comes down to personal preference.
I am also in the market for a set this size and am very disappointed with the quality of conventional "tube" RPTVs. The claimed 1080 horizontal television lines has to be a line doubled 540 raster scans. HDNET looks "soft" on all these sets regardless of manufacturer. The goosebumps you get from watching HD material on a plasma or larger RPTV just isn't there.
For what it's worth, the new 4:3 SONY 40" tube TV KILLED every 16:9 RPTV I've seen with HD material. Too bad you have to deal with those pesky black bars... Good luck.