Actuation Mechanisms for the keyboards:
Razer Blackwidow - Cherry MX Blue (tactile, clicky)
Razer Blackwidow Stealth (not currently listed) - Cherry MX Brown (tactile, not clicky)
Razer Deathstalker - Not mechanical (plunger and silicone dome?)
Alienware TactX - Not mechanical (plunger and silicone dome?)
Logitech G510 - Not mechanical (plunger and silicone dome?)
Rosewill Mechanical - Various. Listed option is Cherry MX Blue (tactile, clicky)
Hope this helps people make informed decisions.