The Sandbox 7 update improves performance. It also has new blood mechanics and simple dismemberment.
Some have reported problems with the installer. Here is a zipped version.
Sandbox 7 introduces several things to improve performance. New resource management, new settings which are hopefully easier to understand, and a performance benchmark that suggests settings. Other features include blood streams and simple dismemberment.
Please try it and share it!
Weapon jamming. Weapons can fail to feed from magazine and into chamber. (Turn this on in extras.)
Reduced recoil on rifles and SMGs.