The key thing to remember with Spotify is to make your playlists available OFF Line the day of the event. This way you can use both players at the same time and you don't have any issues of not being able to play a song because internet access has been lost. This needs to be done with each individual playlist, while still connected to the internet. Once all playlists are made available offline, go to Settings (The gear symbol) and then to Playback and click the Offline so it turns green. Now your playlists are downloaded and you can operate each player independently of the other players.
ITunes is better in some ways, because you download songs from CD's and from Amazon.com and the iTunes store. So you have a lot more options as far as song choice. With Spotify you are pretty much stuck with what they have in their library. Also with iTunes you don't have to make the playlists available off line. They are just there regardless if you are on-line or not. And finally, you only have to spend money for songs you can't get from CD's. Most usually end up spending less than $50 on music. For Spotify Premium it is $10 a month. If you sign up more than 5 months away form your event you have spent the same amount of money.
Just Press Play Productions
Spotify is almost as good as iTunes. In our opinion. It definitely gives you a lot more music choices for a reasonable monthly charge. The paid version is really the best option to go with for Spotify.