For about the last 4 years, I’ve been working through numerous open source products to create my own workflow manager.
One of the main requirements was in house hosting, as the internet infrastructure in Australia remains quite old & slow.
The first one that looked the goods was SugarCRM, followed by many others & I settled on vTiger. That worked well and the vTiger community were helpful & robust. (vTiger was an early fork of SugarCRM).
vTiger released their long awaited version 6 and reduced the community version offerings for quite some time. About a year later, SugarCRM did the same.
With foresight, SuiteCRM picked up the ball & here we are. I was delighted to receive the marketing email today which showed they had been developing the SuiteCRM fork for 2 years now & I must have downloaded the first one. 2 years went quick 
The point of the above is that all of the CRM products look very good on-line, however I only ever found SugarCRM/vTiger & now SuiteCRM were able to accommodate those things that only show up when you’re evolving into a product.
The ability to create complete custom modules is just awesome & most offerings don’t have that or are too difficult for normal I T Support to program.
When you add the work of the SuiteCRM developers to things like that, it becomes quite unbeatable.
I’ve become a little adept at looking through the on-line offerings & it’s quite amazing how “near enough is good enough” is a prevailing philosophy out there.
It’s also no wonder that 80% of CRM implementations fail.
cheers
Ian