23 year-old male from Shakopee, MN -Being an English Major, I love words more than most people. In both senses of the phrase. -I like to eat cake while excruciating.
You wouldn't necessarily have to play Halo Wars, some of the award levels are available if you only play one game. For example, there's one for campaign completion. The three awards levels are for completing Halo Wars' campaign, completing H3 on Legendary, and completing ODST on Legendary.
If you're just after avatar rewards (clothes, props, etc.) and not meaningless awards and badges, those are available only for ODST achievements (so far).
I felt the same way about Waypoint. I thought I would look at it once to see some of the Halo Legends stuff or Reach trailers, and that'd be it. Finally getting avatar rewards is pretty sweet, and I love the badges stretched across the three games like that.
I've only gotten a few of the achievements in Halo Wars so far, but I've got a ton of the little badges on Waypoint. I suppose if you're a completionist you may want to get it.
When you first sign into Halo Waypoint you get the Monitor. If you select the option to link your service record or whatever it is (you'll see it) it will go through the Halo games you've played and analyze your achievements, then automatically award them.
All of the rewards I've gotten so far have been for ODST achievements, and since I mostly play the campaign, I think all of them were campaign rewards. One you get for the "Tourist" achievement, I think I may have gotten the full ODST suit for the "Good Samaritan" achievement or whatever it's called (not killing any Engineers as the Rookie).
You also get milestones for different achievements that appear as badges on your service record on Waypoint. Those are for collections of achievements, like getting a bunch of vehicle-related achievements in Halo 3, ODST, and Halo Wars. And of course there's one for the Vidmaster Challenge achievements.
Sorry I'm not very specific, my Xbox is off right now. :D
I figured you make sense to be an admin seeing as you were either the 1st or 2nd person I made a pic of... I'm not sure if I'm going to do anything with that group or not yet.