Should I exchange my UT50 for 55LM4600???

I currently own a Panasonic UT50 and very happy with it. Although I have noticed some glare I have controlled it for the most part. Basically, here's my dilemma...I got this TV for $699 at Costco and still well within the return period. Costco also has the LG 55LM4600 LED TV on sale for the same price. Is it worth the exchange? How much better or worse is 55LM4600's picture quality? Any input would be appreciated. I have a preference for plasmas cuz I know LEDs cannot beat its picture quality but if there's only a minor difference in picture quality of these 2 TVs but the LED doesnt have any glare issues than it might just be worth getting the LED instead. Smart TV is a good option but its not a selling point since I'll be attaching it to a PC anyway.