Well, after much trial and error and many Google searches to try and find the best way to connect my Galaxy S6 to any TV with HDMI, I think I finally found a Miracast Wi-Fi display adapter that actually works well. First, the ones I purchased that DO NOT work for me:
1. Microsoft Display Adapter: it will not connect to the S6 natively unless you enable the developer mode (see suggestion by Kookie in this thread) and then it only works sporadically and with many dropped frames and jitter. Also will not connect consistently. Even when it is able to connect, it crashes constantly. In addition, there is no way to update the firmware from an Android device; it can only be done from a Windows 8.1 laptop that is compatible with Miracast. Do not buy, this adapter it is not compatible with the S6, at least not with its current firmware.
2. Amazon Fire Stick: It does connect to the S6 without a hitch. First issue however, is that you have to first configure it for Miracast reception via the remote control by navigating to Settings, Display & Sounds and then turning on remote display. This is a time consuming extra step. The second issue is the excessive latency and dropped frames. When I stream a movie from my S6, it is watchable but the jerkiness is noticeable. I was able to stream HD movies from Youtube with similar results on the distortion. The one good thing is that it never crashed on me.
The adapter that worked very well with the S6 was the Actiontec ScreenBeam Mini2. It connected to my S6 right away. I installed an app from the Play Store call “ScreenBeam Utility” and was able to update the firmware from my S6 to 5.2.70 without a hitch. If you read their release notes, you can see Actiontec actively updates their product to improve compatibility (something sorely missing from Microsoft Windows Adapter). The S6 is not yet listed in their supported devices, but it does work. They have very extensive documentation and support on their webpage. I had an HD movie in my S6 and it played with little to no distortion or jittering. This adapter supports dual band (2.4GHz and 5GHz), and it may be one of the reasons why it performs so well. Also, tried to stream Youtube HD movies from my S6 and worked without a hitch. They sell this adapter at Amazon for $49 (free shipping, no tax).
There is a good article by Rafael Rivera (can’t post links, Google search “Rafael Rivera wifi dongles”) who has done extensive testing on Miracast devices. It will give you some idea on the performance of various products. Even though he has not tested the ScreenBeam Mini2, he did test a product (Actiontec ScreenBeam Pro) with similar technical specs and it had the least average latency. He also tested the Amazon Fire Stick and it had the highest latency from the bunch.
To be honest, I was very disappointed with Samsung’s decision to drop support for MHL, but now that I found this adapter, I am happy. I actually prefer a wireless solution to a wired for streaming movies, and this wireless screen casting seems to perform almost as well as wired MHL. I'd like to hear from anyone else that has tried this device with their S6 to hear about your experience...