Panasonic pro - picture quality, even backlighting, no color banding, amazing contrast. Con - reflection (but good antiglare filters), smaller size, image retention potential.
LG Pro- larger size, matte screen / less glare, no chance of image retention. Cons- lesser picture quality, backlighting technology inferior to plasma.
I had originally bought a Panasonic LED tv and could not handle the backlighting / light leaks with letter boxing due to the actual backlight technology. The plasma is perfectly even without any light leak (impossible since each plasma pixel generates it's own light). The biggest deal breaker for you may be the reflection / glare on the plasma. Hope this information helps.