Canon 100mm Macro Lens Difference?

[Bibble]

I'm looking to purchase my first macro lens and am having difficulty deciding between these two:

Canon EF 100mm f/2.8L IS USM 1-to-1 Macro Lens for Canon Digital SLR Cameras

and

Canon EF 100mm f/2.8 Macro USM Lens for Canon SLR Cameras

What am I getting with the IS 1-to-1 lens for $300 more?

Thanks!

[RichardTaylor]

Beside the IS;
Better build quality,better IQ and faster focussing.

[Bibble]

Originally Posted by RichardTaylor

Beside the IS;
Better build quality,better IQ and faster focussing.

Thanks for the reply; I appreciate it.