I have worked with them for over 3 years now, they are always working hard at improving my site's performance as well their own! They're amazing people who work so extremely fast.
When we first started out there wasn't much knowledge about how social media could be used effectively online when it came down specifically to SEO but since then things really improved considerably - even though sometimes some changes might not seem like such an improvement upon looking back later!!? But overall great experience and friendly team :) Great customer support from managers too which made me feel welcome every time i had any questions or issues regarding anything related :).