Hi. I am in the market to replace my 46" 4:3 Mits with a HD big screen. I really like the vertical size of my screen, so I think a 55" would be fine for me. I only want to spend around $2000. Right now I am looking at the Mits. WS55313 for $1788 and the Mits WS55515 for $2399. Is the 515 that much better? I don't need a tuner, since I'll get one from my cable company. Other models I should look at? Thanks.