Welp, Del-ton didn't have any chrome-lines barrels for the Mid-length AR setup I wanted to do, so I canceled the order and after a bit more reading decided to go with a Stag arms Kit.
Supposedly the Stag upper is of better quality components/has better quality control than the Del-Ton. So what i did was design a Del-Ton kit that matched the Stag kit perfectly, and the Stag only came out to being $10 more.
I wanted to get a Stag Arms lower parts kit for my Stag lower anyway (which is like $65, and which I can't get at del-ton) so I just got the Stag kit for $633 shipped.
The main differences between The original Del-Ton kit and the Stag?
Well the Del-Ton I wanted had a Mid-length gas system, HBAR (heavy barrel), and a Magpul CTR Stock. The Stag has a carbine-length gas system, m4 profile barrel, standard stock, and rear flip up sight. Piece for piece (if I wanted to buy each part), the Stag is the better value really.
It's a trade off. The Del-ton has the stock I wanted, and was a mid. The Stag has a lighter barrel (2-3 pounds lighter), comes with the rear flip up sight, and being Stag will fit/match my lower 100% perfectly (not all manufactures upper/lower receivers fit the same, and not all are finished as nicely. Stag has some of the best machine finishing in the industry).
If I wanted to buy a Stag Model 2 Carbine, it would be like $990 after transfer and background check. By getting the lower and other parts separate I'm only spending $834 total, and saved $156, which (at a later time) can go towards other bits I want. And I get to put the thing together myself! That's so freaking awesome!!!


For a basic understanding of how the gas system of an AR-15 functions watch the animation on this page: http://www.armytimes.com/projects/flash/2007_02_20_carbine/ Select "Compare to M4".
See how the gas goes out the barrel then up the tube then back towards the bolt pushing it back and cocking the hammer for the next shot? Well the closer the hole for the gas tube is to the chamber, the higher the pressure.
When the round is fired the powder is ignited. The process of combustion rapidly changes the state of the powder from a solid to a gas (which is at an extremely high pressure). That gas pushes forward on the bullet, propelling it out of the barrel. As it pushes the bullet forward in the barrel the pressure of the gas diminishes slightly as it fills up the space between the chamber and the bullet. That means the gas pressure is directly proportional to the distance traveled by the bullet in the barrel. A bullet that has gone only 5in in the barrel has a higher pressure behind it then that of a bullet which has traveled 10in.

A rifle gas system (like that on the M16) is 13.2in long. On a mid-length it's 9.8". And on a carbine it's 7.8". What this all means is that the gas traveling back through the gas tube on a riffle is at a lower pressure than that on a carbine. We are talking 16,000psi for a rifle and 24,000psi for a carbine (a mid is 21,000psi).
What this all means is that more stress is being put on the shorter gas system. Higher pressure through the gas tube, higher pressure pushing back on the bolt, more force transfered to the shooter as "recoil".
Another difference is that since the gas system is closer to the breach of the weapon (where the round is fired) you get more debris into the gas system from the round going off then you do with a gas system that is further down the barrel. Things like carbon dust, noncombusted powder dust, copper dust from the round casing, etc.This can (in extreme cases) cause clogging of the gas system and reduce the effectiveness of the gas system to cock the hammer, possibly even render the weapon unusable until it can be properly cleaned.
Here is a graphic illustrating the gas pressure as it related to different barrel and gas system lengths: http://ar15barrels.com/tech/pressure-time.gif

Additionally, the way an AR functions, it LOCKS the bolt in place during the time the bullet is traveling down the barrel. What this does is provide a solid seal in the chamber of the weapon so that the only place for the gas to go is forward, pushing the bullet outward, and it does not unlock until the pressure between the barrel and chamber are equalized. Gas will follow the path of least resistance, and in the case of 40,000+psi, it requires a LOT of resistance. If the bold opened up while the gas was expending, it would come backward into the chamber and the bullet would stop in the barrel.
The time the bolt stays locked depends on how long it takes for the pressure to equalize between the chamber and the barrel. This means the longer the barrel, the longer it takes for pressure to equalize on both sides.
So what goes this mean to the gas system? Well it means that the gas tube needs to be able to contain not just the pressure being put on it, but it needs to hold that pressure for the full length of time it takes the bullet to edit the weapon. So for a 16" barrel AR-16, a carbine length gas system not only needs to hold higher pressures, it also needs to hold it longer as the distance from the gas hole to the end of the barrel is longer than that of the mid-length.

Basically put, a firearm with a carbine-length gas system takes a lot more strain/abuse than one with a mid-length gas system.