As you say, it depends whether you're using a home computer or a mobile/tablet. I only use my Apple home computer ( which uses Safari ), which means that when i first joined in June 2014, i had to get a sky converter to be able to watch your downloads. This was fine and it enabled me to take instant pics whilst i was watching. I could print them up which i rarely did because the quality was less good, ( it's better now but still not up to the standard of your 6 or so member pics.
Now, you can watch the vids without downloading, ( as a member, that is ), but you need to remember that without downloading, you have no video to watch as and when you give up membership. You should also be aware that whilst you can also get full screen facility when NOT downloading, ( same as on u-tube ), the camera facility is not available so you can't extract your favourite pics from the video.
Downloading for home computer use, i seem to get identical results with either MP4 or WMV methods so i'm happy either way.

I've tried to explain this as best i can and i hope it makes some sort of sense. Presumably those who operate with a Windows home computer will not require the video converter. They presumably will have a different experience to mine.