Yes, support is definitely an important one. There are other attributes that some professional users care about more than just a simple functional matrix. For

Yes, support is definitely an important one. There are other attributes that some professional users care about more than just a simple functional matrix. For example, I've been in situations where the ability for the professional user to fit the software to their specific requirements over time made FOSS the choice. Even though the initial solution was worse than the equivalent proprietary one. But, the idea that they could develop and improve it over time to meet their specific requirements was powerful.