Coming from an LG BD 390 that got the dreaded "disc read error" after 1-year of use, I then purchased the Samsung c6900.
I must say the Samsung's c6900's scaling abilities seem to be mediocre compared to the LG BD 390, and the settings adjustment in the Samsung's menu's are sorely lacking. For instance, there is no brightness adjustment in the main settings menu, its hidden in the picture settings when watching a movie. Not uncommon though to see these sub-standard user-interface designs in the devices of today. I almost wonder if people that design user interfaces these days have IQ's lower than my cat.
Sorry, but the LG BD 390 has a much better image in Netflix when scaling non-HD content to 720p, or even scaling 720p to 1080p.
Netflix is not a problem with the c6900 on my Internet connection, there is no re-assesment of the connection speed like some report, this will happen on nearly every BD player with Netflix when you have marginal Internet speeds (5Mbps-8Mbps is marginal for Netflix HD Stream), some BD players are slightly worse than others and will do a bit better at connection management due to buffering techniques.
It is also not a proper test to assume that a laptop or PC using Netflix that does not have the same issue of "connection speed re-testing" is a cause to assume that the player itself is not working optimally, because the type of communication that occurs is slightly different between Netflix on a PC and Netflix on an BluRay type device. There is also issues with cheap routers that come with ISP's, these routers often do not correctly split connection bandwidth between multiple devices (known as QOS), see even routers that have no QOS still have to assess and divide multiple Internet connections in a generic manner, and some routers are just screwy and mess up one connection even if another PC is just barely active on the Internet.
If your connection is 10Mbps+ you should be fine, although I haven't tried the wireless mode since I run a direct cable. My connection is around 15-20Mbps.
That said, the Samsung is just OK IMO, a bit over-rated. I will probably keep it since it does the job, plays the BD's that I need, but the image quality is definitely not an improvement over the LG when testing scaling. I cannot compare regular Blurays between the 2 devices since the LG no-longer can read a disc (it's broken), but from my memory the LG looked a tad bit better for Blurays as well, and the LG definitely looks better for Netflix streaming and scaling (which I did compare since my LG's netflix still works).
I am using a 106" screen with a projector, so I can likely see the differences of the image quality much more than you would see on a typical TV. The contrast and color reproduction for scaled images is not as good as the LG BD390 was. I would have ordered another LG, but heard too many people with the dreaded "disc error", and since I already have one LG coaster (now only useable as a Netflix device), then I didn't want to take another chance on having another LG break on me.
The interface is annoying, but not necessarily horrible, it is very LAGGY to respond to the remote commands. The netflix interface is not bad since it at least has a search function, but it is useless to me because they did not include the "HD" as one of the Genres in the NetFlix list, which means I still have to use my home computer to add things to the instant queue.
All-in-all it is just an ok blu-ray player, but the only thing I have to compare it to is the LG BD390. Personally if I had to do it over, I would get a different player, and I am even considering a return, but will likely not return it because I ordered it from a fairly unknown vendor that might not be the easiest to handle an RMA. However, I don't really care about the scaler since I cannot stand to watch NON-HD content on a 106" screen anyways (720p is as low as you want to go for this large a screen).
The one benefit it does have over my older LG is a slightly wider selction of streaming service support (Hulu Plus, Pandora, etc...), but the new LG's likely have added all this by now.
I don't know why or how people are comparing upscaling on small TV's, any differences you would see are very minimal to the eye, you need a huge screen like a projector to really see the differences of what an upscaling device can do, unless you just sit abnormally close to your plasma or TV, but even then it's still easier to see these details on a projector.
I'm not saying you can't tell the difference between 480p and 720p on a big TV, I know you can, what I am saying is trying to see the difference of what a scaler does from 480p to 720p is VERY hard on anything smaller than an 80" screen unless you are standing near point-blank to the device. Remember, the scaler differences are somewhat minimal until you get to really big screens.
The build quality also seems cheap, but honestly it's just a guess, because you cannot tell build quality unless I opened up the device and looked at the individual parts they used (are they using cheapo capacitors that are producing too much heat for instance?). So build quality is a big question mark as with most electronics, the device looks fine from a aesthetic standpoint, but the slimness of the DEVICE does scare me, as I have too much experience with slim devices retaining too much heat and over-heating as the electronics in them get older.
The Samsung c6900 gets 3 stars from me.