Just to sum up the things on this thread:
We have been using SSA in all the supported browsers and devices and following has been the relative experience:
Works best with Google Chrome followed by Firefox and then on MS Edge and IE 11. We also certify it on Safari on Mac and it works fine. We don't certify SSA on Opera but it is good to know that it is fastest there.
For IE 11 in citrix environment, in the screen sharing session with one of our customer we found that the IE 11 was not the latest version and it did not work well because of the memory allocation to the citrix system.
Feel free to share any more information if you face while using SSA on a specific browser.