When you say "compare" are you talking about reviews and features online or do you mean actually going to the store and looking at picture quality? I hope you mean the latter because thats the best way to pick out the tv. I'm pretty big into tv's and I've noticed that everyone has a different opinion when it comes to picture quality so the best way to see which pq you like the most is to go to the store.
Both are quite useful IMHO. You need to have some background info then see how the tv works for you.