Is this good enough to carry combat boots?

If they were lightweight like my Rocky SV2's, maybe. Just not sure it would stand up to the weight. Can't say I've tried it sooo........but worth a try and I'm sure with the GREAT customer service the company has, they'd be interested in hearing the outcome so maybe they can develop a KLITCH for heavier footwear. Hope this helps.

What is with the Gen 2, is it just color or is the clasp differently made?

Truly, I cannot tell much difference other than the plastic SEEMS to be of better quality. I personally have never had ANY issues with all the ones that I have, and I have several, but the original plastic just seemed of lesser quality. The customer service is PERFECT ! I had questions on the product in the beginning and they went above and beyond to answer my questions......which is rare. Hope this helps. I definitely recommend this product AND WILL / WOULD buy it again.