the token system makes it possible to have access control over your stream, e.g. for pay per view?
And you can put a whole lot of logic into Wowza modules.
Any other differences?
The major difference is that you can not really compare the two products.
CDN streaming make sense for a few smaller files that are requested very often so you can be sure that for each request the files are on the edge server. Like a movie trailer for an upcoming release for example. Or the top 10 movies in a popular vod system.
Keep in mind that on each first request the file has to be transferred from the origin to the edge so with files that are less popular you would basically have the same customer experience as with a direct streaming from the origin if not worse. Plus you have unpredictable costs.
Whenever Wowza will have an Ami in the West Coast Region that might be a good alternative with a much better cost control as you would then have us west , us east and eu streaming options that you could fully control eg having a base s3 us east and top 500 files on s3 us west and in the eu controlling traffic flow with a geo module.
But that all applies only to a vod enviroment, live streaming is a totally different story.