Captain_Jack_Sparrow
i'd say it depends on what your knowledge is on CDO. It's all processing js, so more or less the same, with a few key differences:
1) no keyvalues or load image, so no online stuff (for the most part). this is the main appeal of CDO.
2) no sprites. while sprites are just constructors that could be easily recreated in KA with a little effort, the lack of the sprite editor means you have to use pjs art functions like ellipse and pushMatrix/popMatrix (push and pop on cdo). while this means that graphics are a little harder for newbies on KA, I personally think that the vector graphics of KA are better looking.
3) minimal sound. there are libraries people have made to be able to play sounds beyond the basic set of sound effects provided, but you can't just upload an mp3 and play it with a single function like in CDO. personally, i think this is an upside to KA as it promotes more actual programs and less of those trashy pixel art+youtube music 20 lines of code FNAF gibblescrobbleblot versus codemaster whatever things.
while these differences all seem to point towards the idea that CDO is better than KA, this is not taking into account the numerous benefits of KA that CDO lacks. i don't really feel like listing them all again, you can find one of my older comments if you want, but here's the gist of the benefits: faster programs, nicer/more advanced members, actual community interactions, a ton of useful tutorials, contests (official and not), blah blah blah
