+1 here. Spotify Premium is great.
There's a little-known glitch with using offline mode on your phone if you sign in with your facebook account (the default option these days). It's an easy fix once you know.
The symptoms:
You put Spotify into Offline Mode
You put your phone into Airplane Mode
You get on the plane
Spotify works perfectly
You get out the other end, and turn your phone radios back on
You do your work
You go back to the airport, put your phone back into airplane mode, and get on your flight
At 12,000ft you fire up Spotify, only to find that it wants you to reauthenticate before letting you do anything, and you sit the rest of your flight in silence.
The Solution:
Use a Device password. It's really easy. You need to log in to the Spotify website to generate your device password and get your Spotify username.
Details here:
http://www.spotify.com/us/help/faq/devices/connect-devices/The only issue I have with Spotify is that the catalog isn't as comprehensive as it should be. It's pretty good, but there's still quite a bit that you can't find. IE, the older Snow Patrol albums are in there, but the latest 2 are not. I'm sure this will change as they enter in to more licensing contracts with more publishers, but it's annoying that it's still a big problem given the head-start that Spotify had on the competition.
By contrast, the new Xbox Music service has a catalog that's roughly double Spotify's, straight from launch day, for the same monthly fee. It will be interesting to see how they go against each other, once MS get their IOS and Android clients out.
Before Spotify:
Walk up to TV
Fire up media centre PC
Wait for media centre PC to boot
Find TV remote
Turn on TV
Set TV to AV input
Put down TV remote, pick up PC remote
Use PC remote to open mp3 library
Scroll through to find music I want
Put down PC remote, pick up AV receiver remote
Change AV receiver to PC input
Change volume
Set outside speakers on
Walk outside
Walk back in and repeat whole procedure for next album
With Spotify:
Take iphone/ipad out onto patio
Open Spotify, search for playlists
Press play
Change from iphone/ipad speakers to Airplay AP hooked up to stereo
Enjoy music - change volume, skip tracks, etc all from the iphone/ipad without leaving my chair (and more importantly, my drink)
Love it!
Matto