Hello there,
Sorry for the questions, but I’m mixing up both of the CRMs.
What’s the main differences between Suite and Sugar ?
Greeting 
Sugar was open-source, but then turned evil and closed-source. That’s when the fork was made, about 4 years ago, and SuiteCRM was created. A lot of payed modules were added to SuiteCRM for free.
Now Sugar is probably a more polished product (lots of money behind it), but it’s also an expensive product. SuiteCRM is and always will be, free and open-source. The adoption of SuiteCRM has been fantastic (growing community, lots of downloads, installed in both small and big enterprises).