Decided to plump for this product after some extensive research and I'm glad I did my homework.
The ErgoStand has a good large sized 14" fan which produces a fair amount of air circulation and emits a quiet whirring sound, if you are listening to music or watching a video you cannot hear the fan at all. The stand is perfectly sized for my MacBook Pro 15", but I've no doubt it would work just as well for a 17" machine.
As I type this review, the ErgoStand has reduced my CPU temperature from the low 70s Celcius to to the mid/high 50s, a reduction of around 15 to 18c. This is with the fan at only approx. 1/3 of it's maximum speed setting, very effective! [stats from iStat Menus 3]
Other plus features for me are:
4-port USB hub [no losing out on a USB port, also has a 5V AC adaptor socket for devices that requires more juice, adaptor not supplied]
Adjustable fan speed dial
Cable management handles/clips for USB cables
Five position stand, from flat to very upright
Lighweight, around 1Kg
Movable props to support the laptop when the stand is angled
All-in-all, a great piece of kit, well worth the outlay and would recommend to anyone looking for a decent quality product to cool your laptop.