The Haggard's Heroic and their counterparts Kirilenko's Krafty weapons were released in conjunction the Haggard's Heroic/Kirilenko's Krafty costume for the Royals/Nationals. They were part of a cross-promotion with Battlefield:Bad Company 2 and hold the destinction of being the smallest line of weapons released to date. They consist of only a sniper rifle, a sub-machine gun and a machine gun but no "secondaries" and explosives.
Contrary to what less-informed people may think, the Heroic/Krafty weapons provide no advantage over Supers. The BC2 weapons are essentially reskinned Super and Uber Weapons.
The weapons are made to model modern-day weapons whilst the other Tier One and Tier Two weapons are made closely resemble World War II Weapons. Because of this, people assume that since the BFBC2 weapons are made from the 20-21st Century, they are stronger and better (called Self-fulfilling prophecy). The person thinks that he is stronger and doing better, so he fights better. This is not always the case for those who generally cannot successfully win during matches. Some people also just buy the weapons, because they look "cooler."
In the files, the M95 Sniper Rifle is referred to as the "M24", the US Army sniper rifle
The Haggard and Kirilenko series SMGs are in real-life assault rifles, not sub-machine guns.
The "Haggard's Heroic" weapons are based off weapons used by the United States Army and Marine Corps. However, the choice to use the M16 over a more recent weapon, such as a variant of M4 carbine or the HK416 (which was the stock firearm in the original Bad Company). However, it was probably chosen because it's the most readily observable member of the AR-15 family (over the HK416 and M4). Given how the US Military still mainly has a "Good Guy" image, particularly compared to the Russians, this might imply that the Royals are the good guys.
The Kirilenko weapons are based off modern Russian weapons, which was, ironically, an enemy of Germany for most of World War II. Since the weapons are all AK-derived, and a certain stigma is attached to AK-series weapons in Western eyes, it can be assumed that the Developers intend for the Nationals to be the bad guys.
In a manner akin to Dapper and Stylish weapons, the Bad Company weapons received golden variants - like the Stylish and Dapper weapons, this only changes appearance. Unlike the cosmetic first-tier weapons, the golden guns were only available by guessing the correct winner of the 2010 World Cup (which was Spain), as opposed to purchasing them directly.
The AK-74 (more directly, the AK-74M) is referred to in the game's files as the AEK-971, indicating that it was originally the latter weapon.
In spite of the weapon being intended to promote Bad Company 2, the AK-74 does not appear in Bad Company 2 (discounting the AKS-74u).
The Bad Company 2 weapons are the SVD and the M95, which are statistically 100% same as their equivalents, though their soft sound may make you feel like you have less recoil, but this is not true. Also the soft sound may give you a slight tactical advantage, as the enemy can't hear you that well.