While we're still (somewhat) on the subject of Forge. I'd like to point out some stuff that annoys me about Reach's objects. Here's a list of what I'd like to see changed in Halo 4. It's most likely already too late (especially since it seems that 343 is copying objects straight from Reach) but I'd still like it said.
Right here you can see the 1x1 flat, 2x2 flat, 3x3 flat and 4x4 flat next to each other. You can clearly see that they don't have the same thickness. This may seem like a minor thing but it can certainly become a hurdle when creating maps. More consistency wouldn't hurt.
Here you can see the corner pieces. Again, there's no consistency. The 4x4 has a railing on the outer side, the 2x2 has no railing and the 45 degree corner has a glass railing on the outside and a small stick on the inside.
This is the glass cover piece. It's rarely used on any maps mostly because it can increase framerate issues but also because the object is so awkward it hardly ever fits anywhere. Please just make it a simple square window. That way it's actually easy to implement it in your map.
More consistency problems. On the left you see the window object. It's a fairly small window with no glass in it at all. Then we you go to the window, double piece suddenly ~2.3 times the size, has glass and and entirely different aesthetic look. Wouldn't it make more sense if the window, double piece was just the window piece but longer?
I have no idea what happened here. You go from a door to a double door which is just the top part of a door or something. Why not just take the door piece and make it twice as wide?
Ah, the Brace, Large piece. Often used on maps but causes problem because of the tail-end. The tail-end is practically useless and it turns an extremely useful object into a decent one. Please just remove the tail.
Back to consistency problems. On the picture above you can see that aside from the 2x2, short and 2x2 block the objects look widely different. It goes from being made entirely out of glass to a block with a glass circle and then to a block made 1/3rd out of glass. Making them all have a glass circle would be better.
Here you can see how the 2x1 flat piece differs a lot from the 3x1 and 5x1 (why there's no 4x1, I don't know). It looks extremely out of place.
This is probably the worst offender in regards to consistency. The walls are all the same except for the wall, corner piece which isn't even close to resembling the other wall pieces.
So the Ramp XL is 2.4 units long. It really wouldn't hurt anyone to at least extend it to 2.5 units or more preferably 3. It can become really cumbersome to work with a piece that's 2.4 units long and doesn't really fit in anywhere.
Again a consistency problem. On the right you've got the 2x1 ramp and the 2x1 ramp shallow. Both those objects are completely solid. Then you get to the 2x2 ramp and the bottom part of the ramp is gone, the inside is hollow. Where'd that come from? Now you have to fill that up when you use the piece in certain situations.
Lastly, there's the wall coliseum piece. For some reason it seems to be stuck on a different grid then most other pieces when using coordinates on the Y-axis. For example, you can't line up the coliseum wall and block pieces. There will always be a slight height difference between the two. This is fairly easy to fix by manually raising or lowering the wall but it's still a bit annoying at times.
I'd also like to mentioned that overall in Reach way too many objects use glass. It creates a really busy look overall. I personally think it would be better if more objects had textures like the 2x4 block or the Brace Large. Make things a bit easier to look at. Less glass also means less places for lights to bounce off of so it would be (a bit) easier on the engine.
Now these problems on their own aren't that much of a deal but too often in Forge I wonder what the designers were thinking when they created certain objects. Especially in the context of the other existing objects. The lack of consistency in objects size can make it harder for Forger to create sleek maps and the lack of consistency in textures can make maps look really messy. With more objects that look similar you can create a more coherent look for your map which is usually much easier on the eye.