Well, the Pioneer 8th gen are better screens than the Panasonic or the Samsung but they're a lot more expensive. I looked at all the current screen and went for the Samsung PS50Q97HDX because I thought it was the best performer at 50inches. So di What Hi-Fi only a few months back. I paid £1080 for my Samsung delivered and you can buy it now for £930 from Amazon or £952 from RGB Direct. And these prices include delivery.
You may like the Panasonic, but I actually think the Samsung is better and it's even better value.
The choice is yours but I assure you, that at these prices, you just can't lose. Pioneer are better, but for £2500 for a 50inch Kuro, I think I'd rather save my money. The difference just isn't 2.5 times.