During my work as webmaster, I already use other products from Sunnyscript, but found this one being the best of all.
Installation went smoothly without problems, customization was an ease (frontend looks exactly like my client's website) and the features can compare to much more expensive solutions.
My client had some support inquiries sent directly to them (how to use the web-frontend, etc.) and they became answered quickly within one day.
Finally, I'm very satisfied.