When recently testing Unvanquished, I though the overall feel and handling (movement sway, iron-sights, recoil and all that) of the human weapons really felt odd. Now I know it is a work in progress, and will probably get better soon (and the weapon models look awesome for the most part already)... but one Enemy Territory mod (e.g. same legacy code base) that really got that right is/was True Combat: Elite ( http://www.truecombatelite.com/ ).
Now the problem isn't a technical one (the W:ET mod code should run on the Unvanqished engine fine more or less), but rather that the source-code was never released. The original developer (Coroner) sadly also expressed that he would not open-source it at all, and by now the game is dieing a slow death, with Coroner playing around modding COD4 a bit and all the players being sort of desperate for some update to the WET code.
Now this maybe a shot in the dark, but I could imagine a friendly request from developer to developer, to make just the weapons handling code available for Unvanquished integration (which is a totally non-competing game type) might be worth a shot...
I am not overly optimistic about it, but there is nothing to lose, and having that code in Unvanqished would immediately make it quite awesome in regards to human weapon's handling and so on.
Anyways... just a thought. If you try and he declines don't be too unhappy about it, open-sourcing the full mod has been tried really hard before :(