I have premium on the windows client and on the phone.
Best thing about it is def 320kbps streaming and download. I use it on my phone all the time. Sometimes the app will lock up for a sec, but at this point that's probably just my 2 y/o phone rather than the client. On one or two occassions the client (or I may have fucked up) turned off downloading my phone collection, so it deleted all my downloaded files on me (like 2.5k songs)
Windows client with 320kbps is basically the bare minimum you'd want for streaming on pc + some slightly unresponsive browsing. In the past spotify has just removed features for no reason, then put them back like a year later which is really dumb, but other than that the client works for me. Everyone always suggests to use the web client though, so prob do that
For $5 a month it's def worth it tho.
Paladin_IMSif you have a large offline collection of music already, consider google play music. you can upload 50k of your own songs and stream them anywhere (you can also do this free now)
Biggest problem I've had with Google Play is that there's a limit to the number of songs you can have in a playlist to download, so there's no easy way to download ALL of your music without splitting it into several playlists. That said, uploading and streaming your own library is really useful