Last week, I participated in a workshop conducted by Burton Group on Service Oriented Architecture (SOA). I had been using Forrester and Gartner for quite sometime. Recently, I started using Burton Group services.
Forrester conducst many web conferences every year to share their findings. This is nice. Still, their findings do not tell anything new that I did not know about. Also, they normally lack depth. Gartner focuses more on industry trend and also lacks depth. I found Burton research material and this last workshop very detailed and in-depth.
I was also happy to meet with and pick brains of experienced architects who participated in this workshop.
If you are technology agnostic and focused on enterprise-wide governance or architectural work, I highly recommend Burton group. Their licensing is also for the entire enterprise. I find that useful.