Both this to upgrade from my 40" Sony KDL-40V5100. I am as equally impressed with this as I was with the last Sony TV.
The x900f sound is better than the the Samsung sound bar I was using with the last TV. There is a sounds seeing for stand or wall mount, which is a nice idea. The speakers are down facing and my TV is wall mounted.
The picture is good, but takes a little tweaking of the settings to reduce the motion blur. Once set up, the picture is fantastic with quality source content. You won't do better unless you go to OLED, which is twice the price.
The Android TV functionality, I would say, is not optimized, but it still works just fine. There are "apps" button and "home" buttons on the remote. You sort of have to pick between the two menus to find what you want. A few TV settings are only available through the "home" menu and not in the TV settings. A bit puzzling, but not unworkable.
I have always had great success with Sony products, particularly TV’s. This TV is more expensive than other makes but the quality is excellent. Very easy to install and excellent picture quality.