I recently bought the SEO add-on and Blog add-on from 4 Sprung. At first we encountered a lot of problems concerning functionality and other stuff and I wasn't very happy.
Steve and I e-mailed a lot and he even called me on the phone from Australia (to The Netherlands) to talk about thing and which way to go. I really appreciated this. He came up with solutions. He and his developer/support guy put a lot of effort in to make things work and they did.
I want to thank Steve and Sakthi for all their help!