Yes, I have flown both the Kaos and the Dirty Birdy. You are right, the Dirty Birdy has better Knife Edge performance than the Kaos but the differences go way past KE.
Being a later design, the DB refines the performance of the Kaos to include the ever expanding requirements of pattern flying. KE was just coming into the sequence so the fuselage depth was increased. Don't leave the canopy off as many people used to do with the Kaos, it's important to the side area! While the Kaos will fly KE, it won't hold altitude. The DB will hold altitude in a very long KE clear across the field. Nothing like today's pattern planes that will KE loop but far superior to the Kaos.
The DB has a thinned down airfoil, lengthened tail and airfoiled stab. All this combines into a faster, super smooth, slippery airplane. It's much quicker than a Kaos. It is also much slower to slow down. It will slow to a crawl for a landing but you've got to give it time. You need to chop throttle directly in front of you on the downwind leg while down low and make a long approach in order to land nice and slow. Not a problem, just be aware that you can't dive for the runway and expect it to land. Dive for the runway and it'll go sailing past you.
The DB is awesome in snap/spin maneuvers. It is one of my two favorite snap roll airplanes. Using the "accelerated snap" procedure as described in the 1st US RC Flight School book "Advanced Aerobatics" I can hit a 5 turn snap and still pull out in level flight. It happens so fast that most people can't count the snaps. I have an advantage, I know it's coming!
Wind? The DB punches through most anything. Of course, you'll have to adjust on landing and in a crosswind knowing how to fly with rudder is always a lus.
Both of my DB's have been built up from balsa kits. But I have recently flown the DB ARF. As much as it pains me to say so, this might be even better than the one I spent a couple of months building. It was significantly faster but it also had a modern engine with tuned pipe while mine had a very old Magnum. Nothing against the Magnum, it runs great, it just isn't the hottest iron in the fire being about 30 years old. (But can you beat a price of FREE???)
Definitely, the DB is a far superior airplane to the Kaos. I love the Kaos, it's a great sport plane and I recommend it frequently. But for more pattern performance the DB is the way to go.
I'm currently building a Great Escape and can't wait to see the improvement over the DB.
Dave
Last edited by dbacque; 09-14-2013 at 07:54 PM.