Inquiry about your formal employee

Greetings from Japan, My name is Minako. I am considering hiring Dmitry from http://www.diansoftware.com/en/projects. They show on their site, that they developed your site (or worked on it). My project is very large and potentially expensive, so I simply would like to ask you, if I may, if you were happy with the services Dian Software provided you. I understand that I am stranger to you, asking for a moment of your help. But, a quick reply, with just a few thoughts on their service, may help us make the right decision- if this team is a quality, reliable group of individuals. Did they deliver tasks on time? Were they easy/friendly to work with? Did they meet your expectations? Would you recommend them to friends, or use them again? Any help/comments at all about their service would help me immensely. Thank you, Respectfully Minako, Tokyo, Japan