I've had a Kodiak for a couple years now. It's used about 3-4x /month - and it's been rock-solid for me. I have a bigger DIY rig, but the form-factor on the Kodiak is great - light, small, solidly built, and the shoulder strap is a nice touch. I often take it camping, tailgating, and for powering mobile sound systems. I've never really pushed it to failure - but have definitely measured momentary peak loads well past 1500w and it's not flinched. Being able to add external batteries was the primary reason I bought it - sadly, you can only use lead-acid (though, Inergy's new Flex battery can be added). The other downsides are the unusual solar input (Neutrik - which is actually a decent connector, just not common), the PWM controller instead of MPPT.
There are definitely more efficient/better products coming on the market (including Inergy's new Flex modular system), with better warranties - so hard to know what a fair price is.