Advice Requested - Panasonic 50PX14 or LG 50PQ20

I was just in Costco today, looking at the exact same 2 tv's! They were side by side, so comparisons were quite simple. I do not own either brand, so I'm no fanboy of either. I think you'll find most people here will tell you to go with the Panasonic simply because of the better blacks, and Panny reliability. That said, MY personal preference only was the LG. I'll explain. To me, I simply do not like the Panny displays. They are dim and lifeless. I am aware of the factory settings, so no need to lecture here. Just a personal preference. I also noticed that when I walked in C, they had the 54" Panny next to the 55" Vizio 550 LCD. I had no idea when I walked in which was which. Turns out the Vizio had, in MY eyes, a MUCH better picture, and that's not even the new 551 model.
Getting back to the LG - much better pic than the Panny; MUCH better looking than the Panny; swivel stand unlike the Panny; and when I looked for the mfg date on the back of the tv I noticed that they had a cable plugged into the LG, while the Panny was running componant!!! As far as reliability goes, that nod would HAVE to go to Panny in a BIG way I believe, but no concrete proof.
Just my thoughts/impressions fwiw.....

I usually would recommend the LG PQ20 over the PX14(C1). Just my preference. As above I just find the LG's POP and "clean" picture more pleasing. However, the PQ20 may not be very well suited to your application, as it has no anti-reflective coating on it's screen at all. For an outdoor display, reflections could be become a major irritant, depending on the placement and angle of the display. If you are typically watching at night, or if the display will have an angle downwards from your high mounting location then the PQ20 may be perfect. If the sunlit backyard will be visible to the TV behind your seating position, then maybe not so much.

I own a couple of Sammys and Pannys and I feel the Pannys are much more bullet proof. Not a trace of IR, Solid builds, in no way is LG is the same class as the other two. Spend the $50... BTW the going price on the 42X1 seems to be 560-599 on sale, hope Costco is in that range.

The Panasonic has this double-layer antireflective film that dulls out the image when viewed next to the LG -- which, not having any "sunglasses" like the Panasonic, is noticeably brighter. Which should be significant in a semi-outdoor location. The Costco extended warranty helps too.

That said, you sure you don't want an LCD out there? Can't see how "better blacks" would be a factor in that environment.

I agree with you that the X1 may be a better choice, and is likely priced below the Costco model. As usual, I disagree with your opinion of the LG's, at least in the entry level sector. No argument that the Panasonics are likely more durable and reliable than either the Samsung or LG 720p plasmas. Beyond that any return/reliability numbers that I have seen are similar for Samsung and LG. When it comes to PQ in that area I don't think that there is a clear cut winner out of the three. They are close enough IMHO, that price, personal preference, and required features, should be the deciding factors.