Cost-benefit is off the charts. A full, highly complex, highly customized install of xTuple can be achieved at about 1/3 the cost of other proprietary systems. The open-source environment allows a technically-inclined administrator with some programming experience to extend the software in business-specific ways without the use of high-cost consulting. Tech support is great, and bug fixes often arrive in a couple of days after reporting.
The documentation provided for scripting is too heavily geared towards an experienced C/Qt programmer rather than a SQL programmer. There aren't enough specific scripting examples, and too many references to class libraries which don't make much sense to someone with no C/Qt background.
We have put all of our ordering/manufacturing/accounting/finance functions on xTuple, including some company-specific functions that we built ourselves without consulting. We've been running the system for 7 years with great success.
xTuple Postbook is the Best ERP
Postbooks is opensource and it is the best way to start without investing lot of money. It simply takes time to implement and change ways of doing things.
The license structure when it's time to increase functionalities and pay for a more complete version.
High tech manufacturing, High mix low Volume. It was very easy to implement and straight forward. xTuple provide very good support.
Awesome product and business model
Everything (price, features, UI, usefulness )
Difficult to install and get a license (it should be done faster..)