Having a look at Great Crusade and Heresy forums they have added a few tweaks to Marine lists.

Some things I like are having the option to replace ML for Auto cannons at the same cost where ever they are available.
What do you think of this?

Another is having Thunder Rhinos. They are a 0-1 option for most legions and some can take an unlimited amount. They are a +10 pt option for Rhinos.
They are fast and open topped. Is this a good option for Marines and gives the enemy a better chance to pop them?