Total Mayhem takes Total Annihilation, bugfixes and extends it the way Cavedog might have. Early game pace is quicker, many new units added (longtime players may recognise some 3rd-party units), including a whole new 3rd tech level tier. Existing and added units have been bugfixed, rebalanced, re-modeled, re-textured and re-rendered to equal or exceed the standard of the original TA units.
The Spider Pack is being revised for 2012. All models redone from scratch. The Netcaster is stealth (can't be picked up on radar itself) and folds away the radar dish when hit by weapons fire (or when turned off).