I would like to know your impressions about the RH71that you have, any issue with the trackpad or something? Have you played BF3?
The G74SX draws air from 2 openings directly under the base of the display (you'll notice there is a gap between the base of the display and the laptop deck when the lid is open). Shine a light under there and you'll see 'em.
The air blows out the back, mostly from the right side. The left 2/3's of the left side 'exhaust vent' are striated plastic to look like a radiator. But that's okay, there is enough radiator to make it one of, if not the coolest gaming laptops on the market.
http://btoforums.com/showthread.php?t=3525 shows the 2 air intakes (2 inside darker grilles) at Step 5. "Pry up the top case". You can see the radiator (and how it is offset to the right side) in Step 7. "Remove 1 Screw on the WLAN&BT Module".