Several months ago I purchased a Sony BDP-S790 (also known as BDPS790) on closeout. It has been discontinued, but may still be found at some stores or on the used market. It has proved to be an excellent performer once you get it set up correctly. On blu-ray discs the picture quality is simply outstanding, and on WiFi it has also proved to be excellent at streaming NetFlix and YouTube videos.
The WiFi operation is where many users of all makes and models of streaming Blu-Ray players, including Sony, have reported problems and frustrations. Here's how I achieved excellent results.
First, check the firmware version and if necessary download and update to the latest firmware, which as of Nov 2015 is M13.R.0510, Release date 12/18/2014. You can check for updates at Sony's eSupport website for Blu-Ray players. Updating can be a bit tricky. You must first download the firmware file to your computer, burn that file to a blank CD or DVD, and then insert that disc into the player and run it. Sony has good instructions, and if you follow them exactly you should have no trouble.
Second, you may need to adjust the WiFi channel on your router to achieve the best signal strength at the Sony player. To check signal strength, from the initial player menu display on your TV, navigate all the way to the left to Setup, then scroll down to Network Settings and press the round Select button in the center of the Sony remote. This will take you to the Intermet Settings menu. The top entry (highlighted) should say Check Network Settings and Connections. Press the Select button; the following display lists your local network parameters. About halfway down that list is Signal Strength. When I first set up my player, the displayed signal strength from my AT&T Uverse router, which is two rooms away, was less than 20%. By going into the router setup, changing WiFi channels and checking after each change, I found a channel (in this case 2) that gave consistent 75% to 82% signal strength at the player -- a vast improvement.
Streaming video performance has been excellent, with almost never so much as a stutter on my Panasonic HDTV. This has been on a 12mbs Uverse connection, hardly a speed demon, and often with one or two computers also connected.
Some users have complained about freezes where the player simply stalls and will not respond untill the main power is cycled off and back on. This has happened to me a few times, and I think is caused by an improprer sequence of buttons pressed on the remote. Apparently the Sony firmware is somewhat lacking in error-trapping routines and automatic recovery. This has become a more infrequent problem as we have become more familiar with player operation.
A second problem may occur on occasion when you have been running a series of videos and then upon selecting a new one an error message flashes indicating insufficient memory and kicking you back to the main menu. I think this may also be a firmware problem--failure to flush the memory when switching to a new video. This too, however, is infrequent.
Over all, the performance of this unit has been excellent. It is virtually silent in operation, runs very cool, has excellent inter-connectability, and a good form factor. With a bit more attention to its firmware, it would be truly outstanding.