I'm in the same bandwagon as you are, the only difference being my budget is $4000 instead of $5000. And I REALLY, REALLY want to upgrade at least to a 75 or 80 inch. I have looked hard and long at the sets you describe. The samsung set is already out of the question (It's like 8 grand here in the U.S. 7 grand if you're lucky). So that only leaves the sharp, and I was already set on that one, until I ready some lukewarm reviews about it's picture quality and decided not to go for it. (Let alone aesthetically is just fugly in my opinion). And I also want 3d, so that left basically with no options. However, something I completely ruled out in the past might be the answer this time: Vizio. I had a HORRIBLE experience with in the past. I purchased one of their sets and it happened to die A WEEK after the warranty expired, and they refused to give me any leeway whatsoever. So I paid $400 bucks to repair it. Replaced the motherboard. And a few days later, It died AGAIN. Called the tech back, and it was the motherboard again. So the shop that sold me the motherboard gave me a discount, and I ordered a second motherboard, and it damaged it in less than a week. This think was a motherboard killer, pretty much beyond redemption, so that was a total loss. And I swore I would never touch a vizio TV again, not even with a 10 foot pole. Fast forward to today, and my "I want an 80 inch 3d TV and only have 4 grand available" conundrum". Then I found out the vizio M series had been announced. See here:
So that peaked my curiosity, but amongst all the things I've read about vizio lately, this by Sam Biddle from Gizmodo stood out:
"Simply, I doubt anyone will be able to tell the difference between a 70-inch Vizio and a 70-inch [Expensive LCD Brand] side by side"
So it appears to me that Vizio has stepped up their game lately. And the M series looks gorgeous, the thin bezel looks amazing, and the street price for the 80 inch of $4500, puts it right at my price range. So now, I'm seriously tempted to purchased this bad boy once Costco starts carrying it. I actually intend to purchase a Coctso membership just to buy the Tv from them, because my endgame, is this: I'm I'm gonna roll the dice and give Vizio a second shot, I'm sure as heel gonna buy from the place that gives me the best warranty, and I'll pay with AMEX on top of that. So right off the bat, I'll walk out the door with 3 years piece of mind.
There's also a thread here on avs about the Vizio M series, and I will also stop by that thread to gauge the temperature, warranty and customer service wise, from previous vizio owners. Probably I'll just copy and past this post too, see what they think my chances of having another vizio nightmare are, but for what I've read, Vizio is apparently doing things right nowadays.