The armor has always been a big deal to me (not "bigger" than the gameplay, mind you, but a big deal for my personal game experience), in large part because the fictional underpinning of the series is the most important aspect of the franchise, again, to me.
Having lots of armor variations, especially when they make fictional sense, helps to further build the feeling of immersion in the game experience. Personally, I have no problem with the reasons behind not including Mk V or VI, due to the fictional setting. Of course, I do certainly feel for anyone that used those most often. I personally enjoyed using something different than the Chief, because I liked how it made it feel like it set MC even further apart and unique. In a similar way, I never used Mk V(b) for my canon Noble Six, because in my mind, that was for Thom, the original Six. If everyone else looked unique, it seems silly that New Six would just slip into the old V(b) looking the exact same as his predecessor.
Overall, I've really liked a lot of the new armors we've seen so far, especially LOCUS, GUNGNIR, and Orbital. From what I've heard, there will be more sets available in 4 than there were in Reach, which is awesome.
