I just followed the excellent instructions on doing the DX-10 upgrade and also purchased the Add-on converter X package per the recommendation. I feel like I have a new version of Flight Simulator and love the great graphics quality.
One thing I have noticed is that I seem to have lost costline masking. I'm pretty sure this has to do with stock FSX scenery since I noticed a correct coastline when I flew over Northern France which has custom "France VFR" textures. Anyway, I'm wondering how to get the coastlines back?