Raze is way better I think. The only thing witch is better on armor mayhem is the way you can buy armor. I hate the fact that you have to by guns also Raze has better graphics, beter gameplay and better story/missions but I do like the stealing computer date game mode on armor mayhem.
Raze as they seemed to put more work into the graphics and all the external stuff. also because they didnt use HALO guns (not that i hated that about armor meyhem) and made there own.
I think that both have their merits, but personally for me Raze is better. The graphics, the way you can purchase weapons and the skills you can use in Raze 2, those make it better for me. The only think I think could make it better that the guns are a little too expensive considering the low ammount of cash you get per mission in 2. Also, the AI can have access to better weapons than you at the start of the game, which renders the game harder because sometimes they can outgun you, even with your best weapon which can be a little irritating but not a show stopper. Just my personal opinion.