I first purchased an MK Octo kit direct from the MikroKopter Shop (I later found out that the one I bought with the four arms splitting into eight with 'Y' joints was discontinued). The reason I bought it was that I came across a guy in the south of France who was just flying around the beach at a surf competition with his little MK Hexa. I was there with my massive petrol powered heli and his experience was so stress-free and simple.
I bought the kit because, not knowing the first thing about drones ... sorry, Multi-Rotors, I wanted everything required to be included. I actually preferred the look of the Droidworx airframes but knew nothing about motors, Flight Controllers or anything else. That MK Octo was designated toe-in-the-water status to see what all the fuss was about with these MR's. I was not keen to get involved with them because of the battery power - something I have consciously avoided because of the short flight times and the charging nightmare - but that guy on the beach just had such an easy time of it. Also, MR's of this size are very crowd friendly. They don't scare people with noise and vicious scything blades.
There was some initial trouble with the MK Octo that was down to MK quality control but once that was sorted I have to say it flew brilliantly. Nice and calm, very steady, no fuss.
But, I wanted to be able to carry a Canon 5D mk2 and the MK Octo was clearly not designed for that. The plan had always been to get a Droidworx frame if the MK Octo experiment went well. I bought a DW AD-8 HLE because it was widely touted as being capable of carrying a 5D. I stuck with the flat eight configuration because the MK Octo was kind enough to demonstrate how flat eights can stay airborne when a prop breaks. Sticking with the devil I knew, it is equipped with MikroKopter electronics and the recommended AXI 2814/22 motors. I also added the i2c isolator board for even more protection against a motor or controller going bad.
The Droidworx has been the subject of quite a number of posts as I tried to get it to stay in the air for an acceptable period of time without getting all hot and bothered. A few mods later it appears to be behaving much as it should.
So, to answer your enquiry this is my conclusion. The MK has a poor and flimsy airframe and is not conducive to too much modification or improvement. But it does work pretty well and is at the lower end of the price range. The Droidworx airframe is altogether more robust and rigid, plus it really looks the business. Their design is also more conducive to modification with more space to work with. Much more flexible altogether.
You can find lots of stuff about folks' preferences in Flight Controllers and electronics and trail-blazing new systems around these pages but for my money, despite their somewhat poor track record in customer care and quality control, the established and mature MikroKopter electronics do take a take a lot of beating. If you follow the instructions it does all work.