Yes it works,
Yes it can be customized
Yes it have SEO benefits
Yes Support was responsive to issues / questions
I have been a user for the past 3.5 years, and had been waiting for 11 months for updates that had been discussed because I felt things were lacking...
When these finally came around, to get them you had to agree to an increased price. So essentially, they shunned their existing clients. Sure it is a business decision...
This is why I scored them at a 3. I think their product is a good product, but I will not stay with a company that operates this way. What will they want to charge existing clients when they do their next update?
I also found that when making site changes (themes) the UX broke quite easily, so be sure you are happy with your site design, this plugin doesn't switch around themes easily.