I am an FSEconomy user too, and I must say that using Latitude with FSE adds a lot of fun. Typically I use FSE to choose the airplane/route/payload and then use Latitude to setup the flight.
The fun starts when you realize that to have good Latitude scores you really need to optimize the airplane/route/payload and the type of flight (ferry or charter). In a sense, I use Latitude as a substitute for the quite crude earning score you get in FSEconomy.
It will be very interesting to understand how/if SimAir will be a replacement of FSEconomy and how it will integrates with Latitude, but I guess we will have to wait for the release date to have an answer. Personally I am probably not very interested in the Virtual Airline/SimCarrier stuff, but I am definitely interested in everything that can add more reality to my flights as a private (virtual) pilot.
Cheers,
PB111