Macbook Air for Tether Shooting?

[papayaaa]

Hi everyone!

First thread here but hopefully not the last!

I am greatly interested in purchasing the light Macbook air 13'' - 1099$ (see it here: MacBook Air - Buy MacBook Air Notebook Computers with Free Shipping - Apple Store (Canada français)), to shoot tethered using Lightroom.

I already own a 24 inc. iMac from which I do all my editing.

Do you think it will lag or that I should go with a Macbook pro?

If so, can you explain me why.

Thanks a lot!!