The Sphere product page has a wealth of information and provides a good overview. Don't forget to watch the Sphere intro video at the top.
Sphere L22 Product Page
This blog covers the new features added in Sphere version 1.4.
Townsend Labs Releases Sphere 1.4 Update Adding Ten New Mics
The Sphere User Guide has lots of great info.
Our Sphere Whitepaper goes into the technology behind the product and covers all of the features in more detail.
Sphere Technology Whitepaper
To try out the Sphere plug-in you can download it here. Also available are prerecorded L22 audio tracks so you can try even if you don't have an L22 microphone.
Sphere Plug-In Download
For additional answers check out the Sphere FAQ.
Sphere reviews from magazines and other media outlets.
Sphere Product Reviews
The Sweetwater website has a large number of Sphere customer reviews. Many of the reviews are quite in-depth and provide a view of how actual customers are using Sphere.
Sphere Sweetwater Customer Reviews