I purchased these boots back in 2009 and they STILL look brand new. The chocolate brown is a beautiful rich color. The boots keep your feet very warm and comfortable. I read several reviews that said these boots run a little big and I agree. Typically you want more room in a boot because you will be wearing thick socks.
Now I have a pair of Uggs as well and here are my observations;

DURABILITY OF SOLE: the sole on the Emu boot is a tab thicker

STITCHING: Emu boots are double interlocking stitched, while Uggs are single stitched. My uggs are starting to pull slightly at the seems

ARCH SUPPORT: Emu boots have a support for the arch of the foot, where Uggs are flat

GRIP: Although the pattern on the bottom of the Ugg boot is quite flashy, it does not help you on wet or icy surfaces. The Emu boot has better grip

WATERPROOF: Although neither boot is supposed to be used for heavy snow or rain, Emu boots do a better job of keeping your socks dry

PRICE: This one is obvious, this style of Emu boots is $90 - $115 where the same style in Uggs is $160 - $190