gMax is old old and no longer supported. Blender is a work in progress and one day some kind person my develop a fork just for Trainz. Unlike gMax, there are dozens of superb Blender tutorials out there. The most difficult thing is to overcome the problems with moving objects on the screen. It's a bit like learning to drive, but once you get the cordination part down pat, the drawing side is straight forward enough. I'd just love to see some Trainz tutorials on textures and actually moving items across to Trainz.