I own a 30 inch Kobra (Kumar) and a 25 inch Kobra (Kumar). I think that Tom was right, that they both will do most jobs that a Khukuri was meant for, except use as a heavy duty axe or taking apart vehicles or oil drums. It really doesn't have enought thickness to properly pry or bend it self out of heavy wood or metal. It will cut most 6 inch trees and a lot of other things in the woods. However, like Bob says, they are a bit blade biased, and require a pretty strong arm. My 30 inch weighs in at 2 pounds 10 ounces, and the 25 inch at around 2 pounds or a bit less.
But one of my favorites is a 22 inch Kobra that seems to have the advantage of long reach and inherent toughness. It is a lot of fun to play around with, and my wrist and arm don't hurt afterwards.
However, if you review some of the tests at Howard's Khukuri FAQ, you will find that the Kobras and Sirupatis have some disadvantages because of their light weight and length. I personally find that anything over 18 inches long tires me out and doesn't actually cut very well (for me at least)over the long haul. Something about finding and keeping the sweet spot on target. Granted, the Kobras and Sirupati excell at Martial Arts and fast cutting. But I like my 15 inch blades for general work, with my UBE an outstanding example of minimalism in a large blade. It cuts better than the 18 Ang Khola that I owned!!
So, decide on what you want your blade to do then purchase appropriately. Oh, and remember that when you buy your first Khukuri, it will definitely no be your last. There just isn't any such thing as the "perfect all around Khukuri". I managed to buy 15 in the first 2 months I started attending the Cantina!!