David,
Quovadx has the most robust, flexible and escalable interface engine that I could find in the market for the volume of data that we move (+3million messages/day, +1000 interfaces)
The GUIS are easy to understand and very few times we had to ask for support, but it was a positive experience when we did it. We find this forum an excellent support tool. Most of the simple questions, if not all, are already answered and I find easy to search its archives.
Carlos Pardo
Integration Services
BJC HealthCare
cpardo@BJC.ORG