I'll throw in my 2 copper on Octopus.

Ease of Use: 5*
Key Broadcasting: 10
Mouse Broadcasting: 9
Picture in Picture: **
Author Support: 5
Community Support: 8
Technical Skill: Low

* Trial-and-error config with tutorial assistance is probably its biggest drawback.
** It has PiP but I've never used it.

The key/mouse broadcasting have been glitchless for me over >6 months of use. No stuck keys, no "spinning alts of doom," hardly ever have the "runaway" problem, modifier keys always work the first time and never get stuck, no crashes or wierd lockups/cursor problems/keyboard problems/etc. Plainly put, it Just Works(tm).