There are four types of dropsuits: Scout, Assault, Heavy, and Logistics.
Scout: The Scout suit is a light weight suit that is made for mobility which is done by sacrificing protection. There are also stealth perks that go along with the scout such as radar jamming, but primarily this suit is used for fast moving across the map. However this suit lacks the CPU to carry anything other than small arms.
Assault: The Assault suit is the jack of all trades suit. It provides good protection, and solid mobility. It is capable carrying a range of weaponry from small arms to anti-tank and logistical support.
Heavy: This is the Juggernaut suit of the game. It has high levels of protection, has a very high CPU, so you are able to carry anything in the game. However, this suit is extremely slow and bulky.
Logistics: The Log suit is very similar to the assault except instead of carrying weapons, the wearer of this suit will be able to carry more support items, and will be able to hack turrets, NODs, and vehicles much faster than any other dropsuit.
Every suit sounds amazing in their own way, and they are up to a point. The Heavy suit is by far the most disadvantaged suit in the game. All the massive firepower it brings is quickly neutralized by how incredible slow it is. The armor it comes with is higher than norm, but not by that much. Making the risk vs reward for this suit not very good. If the suit becomes damaged by a grenade, its armor level sinks to that of the Scout, and after that it is very quick work to kill the wearer of the Heavy suit.
The Scout suit is third in my book, and it only beats the Heavy suit because of the flawed shooting mechanics, which makes it extremely hard to shoot a Scout wearer. However once shot, its pretty much game over. The stealth perks are nice until you get within the line of sight of someone. Most of the suit in the game have a very futuristic techno look to them, so trying to sneak across a sandy colored map in a bright white and green Scout suit is almost impossible.
For me it is almost a tie between the Assault and the Logistics. I only pick Assault over it because of my style of play is more front line than support. The balance between protection and mobility are what makes this suit really stand out from the rest. In the assault suit you are able to better avoid getting shot, and also when you are shot, it is nowhere near as devastating as it would be if you were wearing a Scout suit. Also, most people choose a Scout suit because they want to play the role of a sniper in the game. The assault suit is able to utilize the sniper rifle, and provide much better protection, which almost makes the Scout obsolete. The Assault suit is also capable of using anti-tank weapons, and also medical support items as well. Meaning you can kill a tank, help a friend, be very mobile, be protected, and carry the needed firepower to fight in the trenches. All this adds up to make the Assault suit the clear victor, and the suit you should use if you want to be successful in the world of Dust 514.