Sorry if it came off sounding a bit "ranty". That wasn't my intention... I was wanting some opinions on an optimal architecture in a constrained environment.

My personal experience has tended to vary from two extremes -- either very small, single server environments (mostly doing pure development work) or very large enterprise environments running business critical reports. I'm not used to the "in between" situation. Personally I would have thought in terms of making compromises, separating application and database layers would have been less important than having separate development and production environments.

I guess I was hoping for some practical experiences... what are some of the reasons for having a separate ETL server (beyond performance considerations)?