I have these exact 2 TV's and actually found this thread for comparison before getting both of them. Here's a quick rundown of my impressions. Just a side note, I 'did' tweak my LG to get better blacks via the procedures outlined here: http://www.avsforum.com/t/1372479/lg-plasma-panel-tweaks-for-better-blacks
The Samsung is brighter. On brighter scenes, it does appear that the Samsung has more 'pop' in its picture. It has slightly better color saturation, although the skin tones on the LG seems more natural to me during certain scenes. The E530 does have more noticeable buzzing if that's a big issue for anyone; it wasn't for me.
The tweaked LG clearly has better blacks, a few distinct shades darker on a mostly black screen, in fact (sorry for not being able to compare stock black levels; maybe I'll change it back for stock comparison's sake). The LG has better motion handling. The difference isn't noticeable most of the time, but during the dark city scene in "Samsara," (middle part of Scene 10), panning on the LG was smooth; on the Samsung, it was decidedly jerkier and had remnants of motion blur. This was tested using the same blu-ray player for each, by the way.
So if I could simplify it, the Samsung looks better in a bright environment, and the tweaked LG looks better in a darker environment. I use the LG as my main movie television as the jerky motion handling on the Samsung was a deal-breaker for me. Most of the time, however, side-by-side, the picture quality is pretty similar.