Choosing between Rdio and Spotify

Update 28 January 2015: Well, it's been almost three years since I wrote this. A bit has changed on both sides of the game. Rdio is still the most beautiful choice, but no longer intuitive, reliable, or moving forward in an particular way. Both services don't get enough updates. That being said, Spotify is the most consistent of the two. It now has gestures, which I find to be very useful for queuing things quickly. Rdio's Play Later feature is still great, and a more visual experience, but takes too many taps. I really like that both services offer student plans at $4.99/month. Despite all the new things, it's still somewhat of a toss up between aesthetics and reliable functionality. Though, to be fair, Spotify crashes a bit too often and uses way too much space for its cache.

Now, for the original article. All pros and cons have been updated to reflect the current featuresets offered by each service.

In the past few weeks, I've had a lot of trouble deciding between Rdio and Spotify for streaming music that I don't want to purchase. Even though they're both great services, I'm still having trouble deciding what I want to sacrifice in order that I may pick up a certain feature on one of them. Also, I don't want to go paying a month fee for both services -- this is a tough decision.

I've compiled a list of what I like about each app to help out all those potential users out there. You can find it by reading more and I hope you enjoy it!

Rdio

What I like

The user interface is just beautiful.
Users seem to put together much better playlists here than on Spotify.
It has an iPad app, Spotify has a (terrible) iPhone app.
Constant quality of 256 kbps, which beats Spotify's varying bitrate.
It's much more social than Spotify and doesn't require Facebook.

What it needs

A better music selection that matches Spotify's. Right now it weighs in at 12 million tracks, which just doesn't cut it.
Something better for its free plan. Right now, it will let you play an acceptable amount of music, but not enough for true listeners. What's nice is it doesn't have any ads at all, though you only get 30-second previews after it's over so I'm not quite sure which is better.
Better sound quality would be nice -- I'm an audiophile.
A private session option for those who wish to hide what they're listening to from their Facebook friends without manually deleting it -- believe me, it's kind of useful.
Higher-definition artwork for meticulous people like myself.
Support for sharing what you're listening to from your iTunes library, even if it's not in Rdio's library.

Spotify

What I like

It's completely free if you don't need mobile and don't care about high-quality audio, but there are annoying ads that you can't skip or even turn down the volume during.
The great Facebook integration. This is literally unbeatable since Facebook partnered with Spotify to make it a special service that's kind of exclusive to it.
It has 15 million tracks and there are many I want to listen to that exist only here.
Much better sound quality on some tracks, but it can vary from 160 kbps to 320 kbps. The latter is great while the former is just plain terrible. I can tell the difference, but some people can't.

What it needs

The user interface isn't ugly, but it does need some help.
I can't stand the weird jolty scrolling on OS X. It's like Firefox and Opera all over again. Who forgot to use smooth scrolling that bounces when you reach the end? It's a must for OS X apps!
More music. Even though it's good, there are still many lacking artists.
Support for sharing what you're listening to from your iTunes library, even if it's not in Spotify's library.
A better high-quality audio plan that doesn't cost $9.99 per month.
A much better way to share to Twitter. Right now I have to type the message, click the share button, wait for the browser to open, and click "Tweet". That's a bit ridiculous and things should be a lot simpler.