You're not missing many other differences... the KSDB is a much better value. I think it's safe to say most of what you're paying for with the KDRS is the look. I have not seen the ranges in person so can't comment, but I would guess the KDRS is also more solidly built, has thicker metal, etc.

I wouldn't put too much weight on oven capacity, it's a big marketing game all the manufacturers play but it really won't make a difference for most people.

Some other differences:

The KDRS has a real high temperature self cleaning cycle. The KSDB has the "Aqualift" self clean instead which has gotten many negative reviews for not working as advertised.

The KDRS has a real meat probe that is wired into the oven controller and therefore can shut the oven off automatically when done cooking. The KSDB comes with a standalone meat thermometer instead, presumably to cut down on manufacturing cost. It is a wireless meat thermometer, though, so you may prefer it over the hardwired probe.

The KDRS has 3 "power burners" overall (15K, 15K, 20K), the KSDB has 2 (15K, 19K).