Been using Syncfusion for a variety of projects for iPad web apps and C#/MVC web sites, and controls are consistent among platforms, that means when you learn a control you learn it for other platforms as well.
All controls are well documented (online and Offline version), so you don’t need to worry about creating developer guides for controls and you only focus on what you have created with their controls.
Free E-books (around 130 at the time of this review) and White Papers provide a great learning tool with specific applications of their tools to BigData, Business Intelligence, mobile development and other topics.
Community Edition Software: For small software companies or single developers, the community edition is a life saver, since you can create a better product without the need of purchase licenses (only for less than 5 users and less than $1 million USD in gross revenue). The Community Edition has all same features as the paid version, access to the support forum and updates.
1. Check the demo section on their website: http://samples.syncfusion.com/
2. Create and account and download/install the trial version.
3. Download specific E-Books related to the language/platform you are planning to use and read them, following the examples (if provided).
4. Check the Online Documentation on their web site (is under Support).
If you like what you see go head an try using Syncfusion on one test project to have a taste of the controls.
Hope this helps you to make an informed decision about selecting Syncfusion. This worked for me.