I will probably be in the minority here. I had the Panasonic DMP-UB900 and now have the Samsung UBD-K85MC (the Costco version). Some background info first. This summer, I got tired of waiting for Panasonic to release their 4K player in the US, so I bought the Samsung and Exodus Gods and Kings 4K bluray. I found the Samsung to look way too dark in 4k, but found it to be an excellent bluray player equal to my Oppo 105D. I could not get over the darkness of the Samsung so I took it back and waited for Oppo to release the 203. Oppo botched my order, charging me for 4 of the 203s, then delayed shipment of my unit, so I told them to cancel the order. I then picked up the Panasonic while it was on sale. I popped in a bluray and was disappointed at the image. I thought the Samsung did a better job at upscaling blurays and my Oppo 105D was easily seen as a better bluray player. I put in Exodus Gods and Kings and thought I saw a more refined picture, but the player was still way too dark in 4K. I decided to give The Martian a whirl and saw banding in the opening scene. My LG EF9500 has known banding issues just above black, but I see them very rarely with a 1080p bluray. Given the cost of the Panasonic, its subpar bluray upscaling compared to the Samsung and the Oppo, and darkness of a 4K picture, I took the Panasonic back and decided to live with standard blurays.
I was advised here on AVS to engage dynamic contrast on my display so 4K blurays would not look so dark. I got a $25 off coupon from Costco and decided to give the Samsung another shot. With the $25 coupon and Costco having a sale, I paid $167 for the Samsung player that included a 4K hdmi cable. I no longer feel the picture is too dark with dynamic contrast engaged on my LG and now I see what all the hoopla from 4K is. I watched Oblivion on 4K and the HDR blew me away. I am now a convert to 4K HDR and WCG. I don't see any banding on my OLED with the Samsung, but that may be due to me learning how to adjust the picture settings for 4K. I think I got a smoking deal on a 4k player. I don't have any issues with the Samsung and the disc drive is very quiet. I am satisfied with my purchase.
The remote on the Samsung sucks. No mistaking the Samsung for an overbuilt videophile/audiophile deck, although the finish is nice. I like that the Samsung has a slim profile so it can sit underneath my TV on top of my TV stand. I also like the GUI on the Samsung in that it shows you an icon of the disc in the drawer. The samsung will not show you the bit depth, color space or audio codec of the 4k disc being played - I wish it did.
The Panasonic is a better built player. The remote is light years ahead of the Samsung and is back lit. I like the digital tube effects that the Panasonic can apply to audio. The Panasonic has a lot more controls you can tweak. I can not justify the price difference; however. The Panasonic in my opinion is not 3x better than the Samsung.
I am waiting to see Sony's 4k bluray player and hope it is not outrageously priced. I think Sony has the best video processing and may consider picking one up if I can see the better processing. I might even pick up the Panasonic if it goes on sale with a deep discount this year when it is phased out. For the price I paid for the Samsung, however, its price to performance ratio is pretty high.