I gave both the entrances last year. I would say that KCET is way more easier than COMED-K.
In KCET, you have questions that are directly picked up from your NCERT textbook. So it mostly depends on how thorough you are with your NCERT. The questions here are straightforward with not much twists and turns.
In case of COMED-K you have to do some more thinking to crack the answer. The level is a notch higher than KCET.