MJ, I'm sorry, but I disagree with you as far as keeping the Gatling gun Senti only. Senti's get everything the Raider and OR's don't get. It's not fair for us non-Senti users. Come on, as if iOD, the Mortar, and insane armor isn't enough for one class. The Gatling gun should be on the Raider and OR, not the Senti.
Sorry for the late reply but,
You can forget how easily the Sents can be MA'd because of their slow movements. Before you say iOD counters this, I meant it mostly towards the dueling areas, because iOD can really just screw you over and contribute to your death.
Although in the capping area and (somewhat) chasing area, I can see your reasoning.
Note: The main reason chasing is only somewhat good is because the mortars have such a long range, but for capping, iOD is terrific for changing directions, yet countered by the fact that the chasers also have the ability to OD along with boost frags.
Also, Mediums and Lights have their own exclusive weapons; The Cluster(M) and the laser rifle(L):
Clusters have now made it somewhat easier for defending(Because of the Cluster "Mines") and considerably less hard when chasing(unless you miss alot.... which sucks for you

)
Laser rifles are terrific D weapons and now as of the public test server, it is a terrific chaser weapon(Which can be demonstrated by a few players that have destroyed me over and over again)
Note: I put quotation marks around "Mine" because they are not detonated as you pass over it.
The only thing I can see you REALLY hating the Sent for is flag play. Other than that, all the other details are more minimal in terms of annoyance.
EDIT: I forgot in my post to answer to Gatlink being senti only;
Imagine a Light being able to get into your face(which they already do) and gatlink-gun you until death, barely ever missing because of such high manuverability.
Of course, you could say Sents counter this with iOD, but there is a delay between each iOD, along with the fact that it will take an immense amount of health to stay in one's face.
EDIT 2: Made some corrections/took out a few sentences here and there, not sure I got everything though.