One of the main reasons imho why the Nex is soo overpowered, is because it shares the same ammo with 3 other weapons - Crylink, Electro, HLAC. This means if you pick up ammo for those weapons, or the weapons alone, you get ammo, so it's very easy to stack up ammo, and it's cheap to use.
My proposal is to add another ammo type for the Nex. In the Quake series, where the Railgun stands for the same purpose ammo is very scare for the weapon, you can't have nearly infinite shots, ammo count is limited in relation the damage it can do. Realy, ask yourselfs, in case you didn't camp, when was the last time you've ran out of ammo for the Nex?
I realise adding a new ammo type would break all maps stock and third party, and also it'll be a huge work to migrate them, the code needs to be written, a good looking model needs to be created etc. etc... but I offer my services for the work: I can take my part, I know how to map, maybe I know a little bit about balanced item placement (and also, I'm not afraid to ask better players for advice), so in case this idea goes through, I'm here to migrate ALL stock maps and the popular third party ones too. (think about it, this is a one in a lifetime offering, you can't miss the opportunity

Advices, ideas, cultivated discussion of the topic is welcomed.
