I got it a couple of years ago because its ability to play most of the formats, including 1080P MKV and ISO, support for most of the subtitles and had a chance to test it before buying. I still haven't really looked closely at the apps like youtube, weather, news, etc. since this is not what I am looking for in a player. I have a notebook running on my desk and a smartphone and that is their job. The only minus that I see is that it takes a bit long (30 seconds) to boot.
I like the option for internal hard drive and its size. I can take it on the road without extra wires and storage to carry. Also, I do not want to depend on the network speed (even though it is wired) while watching a movie. In 95% of the cases I upload the movie into the internal hard drive to watch (it actually syncs automatically from my notebook's folder when player starts and notebook finds it). Another 5% is from USB stick which is 3.0 and it just much faster to copy if I want to watch something right away. So, for my current needs, I am good with my Slim S1. I do not remember a single time when I had to reset it.
so, if you ask me if it works well for me -- yes
does it all *I* need -- yes (no 3D, apps, blah blah)
am I [still, today] happy with it -- yes
If it happens so that I need to buy another media player soon, I again will be looking for small one that can take an internal hard drive (Android or not - does not matter to me), does its main job good, supports most formats, does not hang
and has a USB 3.0 port.