"Features are not everything"
This is an important point!
If your main goal is to produce models for gamestudio why use either one of these programs?
MED can be difficult to use at times but you don't have to worry about export/import and it cannot be more difficult to learn then Blenders' bizarre hotkeys or truespaces' bizarre icons!
So I would still say stick with MED or try milkshape.

Edit... I stuck with blender after trying truespace and carrara a short time ago and one reason was that blender used fewer computer resources. I could do basic modeling on my laptop with blender when truespace and carrara froze the system. I have never seen a discussion on the relative hardware requirements of these apps though.