I've read in several previews that the range of the radar around a Spartan in multiplayer has been reduced. I don't have any good way of quantifying that, but it certainly seems to be true to me.

In particular, on Valhalla there are two rock outcroppings on either side of the stream where players often like to perch with ranged weapons like a turret, sniper, or laser. Often there's a lot of activity far away that they are paying attention to, and more than a few times I've run right up to such a player from behind and assassinated them if there's no one covering their back. It's also happened to me quite a few times as well.

I have a feeling that the radar may have lost most of its usefulness in many situations if this is the case. It can tell you if an enemy is nearby but on a different level, but doesn't indicate whether it is higher or lower, so this is of little use. Out in the open, you'll see a player long before he or she ever shows up on radar, so it's only good for detecting someone outside of your line of sight. If the range is so short, however, that it's routinely possible to run (not sneak) up to players and melee them before they have a chance to register an enemy on the radar, it makes me wonder if it shouldn't be either removed entirely, given a greater range, or provide additional information, such as the elevation of a target.

I'm also of two minds about the new selection of grenades. Frag grenades appear quite dark and are easy to miss in many areas. Thankfully, they have bright red dots that help you locate them. Spike Grenades are rather large and obvious compared to the others, and are nearly always easy to find. Not so the fan favorite plasma grenade. Something about their appearance now seems to make them nearly unnoticeable. Perhaps they also need some part to glow a bit more brightly?

Having two each of three kinds of grenades is also a mixed blessing. Because of their different characteristics, each kind needs to be deployed differently. Because you only have two each of any type, it means you get a chance to miss once and try again, but then you're done. Also, the addition of a third type makes the result of hitting the grenade cycle button difficult to predict.

Before, you had only two types, so the grenade selector was in one of only two states: frag or plasma. If you'd started with just frags but just walked over some plasma grenades (hearing the distinctive sound and seeing the on-screen message) then you knew you had a choice. Pressing the button once changed to plasma grenades. Since you knew the initial state and knew the choices available, you could know the new state without actually looking at the indicator. If you had plasma grenades, the button switched to them. If you had none, it did nothing.

This isn't true anymore. If you have frags and pick up spike grenades but no plasma grenades, hitting the grenade cycle button once switches to spikes. If you have all three kinds, it switches to plasma. From that position, if you had plasmas, it takes two button presses to get back to frags, but only one if you had spike grenades. If you had plasmas but no spikes, then again it would take only one press. In short, it's no longer possible to be completely assured of what you're going to throw without actually looking at the screen.

The same is also true of what happens when you've thrown the last grenade of a type. In Halo 1 and 2, since there were only two types, you basically had a "preferred" grenade type and a "reserve" grenade type. Once you'd thrown all of one, you switched to the other without having to press a button. If you picked up any of the preferred kind before completely running out, you never had to give the game any input to maintain that grenade preference.

If you're throwing spike grenades and run out (more likely now because you only have two of a kind instead of four) what your next throw will be depends on what you're carrying. And if you don't like what the game gives you next, you have to override that with a button press.

Some of it is just the inevitable increase in complexity by adding a third option; just as with equipment and heavy weapons, there are additional factors to pay attention to.