I haven't noticed any increase in difficulty in lowend missions with a
1. newly created rad/rad defender
2. lvl 14 FF defender who SUCKS soloing but i went ahead and did some anyways
3. lvl 18 Inv/SS tanker
All these guys can solo missions now, and they're FUN instead of just tedious (except for the ff defender, still kinda tedious :P)... Before it was 'click, kill , etc etc'. Now I have to play the game.