They are really good at Sniping you from such far away if the map is big but there Cannon is no where near that bad as the Primes and Sicons. For a Rachni I would replace them for the Alpha Male Rachni from Mass Effect one. Voted the last one option.
Brad Pitt, There's no silencer on that shotgun. How are you supposed to kill anyone softly without a silencer? XBOX GT: Player1mj117. PSN: playmaker45.
Other: most everything except armor and bulkiness. Armor is easy to cut through after breaking their sacs, and their size just makes them easier to hit.
My biggest problem is when I'm using the shadow. I can't SS them until after breaking the sacs, and once you do there isn't really a need, as they're usually halfway through their armor anyway. The acid puddles tie into this.
My biggest problem with their guns is their accuracy. They can thread the needle from across the map a little too easily. But I have discovered that they don't like taking close range shots. If you get right up in their face, they'll try to back away from you before shooting. As long as you stay close enough to hug them, they'll continue trying to back away. They may still shoot, but that close they can only hit you with one gun (I've run up and just stood there with the kroguard as a test; it fired, but the shot from one gun just went right past).
Swarmers are only a pain when your getting tore up fighting other enemies, and they crawl up and add that little bit of damage needed to down you. Doesn't happen often, but when it does, it's always at the worst time.
There are 10 types of people in the world. Those that know binary, and those that don't. GT:Talon Omega. If you send an FR please tell me where you got my GT.