i bought the griffin elevator...the brushed aluminum is nicer looking, i think, than the clear icurve plastic. (not to mention that i think the icurve has been discontinued in lieu of the elevator)
it's helped temperatures go down by maybe an average of 5-7 degrees celsius. not too significant, but the main things that it has improved are a freed up desk-area, nicer aesthetics, and i like how it puts the display on an angle. i also route all my cables through the back of the elevator so that it doesn't look so messy.
i came from the pile of books solution to this, and it's nice, but i have to say that the price they charge is utterly outrageous (order from website, enormously bloated shipping costs + tax and conversion to canadian dollars). i will accept being ripped off in this case, however, because it think it is a positive addition to my workspace...i can't think of how it could really be improved (other than the goofy griffin logo on the plastic base)
i can send a picture of what the mbp looks like on the elevator in my case, if anyone's interested...just pm me.