Especially for rondi -
We took Kiev as a post trip and thought it outstanding - certainly equal to either the Moscow or St Petersburg experience. Just a bit different -
We chose not to do the open air museum trip, largely because other tours which have had similar optionals, have been disappointing for us. Almost everyone else went - I think that perhaps only seven or eight of the thirty five post-trippers did not go on the optional. Those who did go seemed to have enjoyed it. But ---- we thoroughly enjoyed a free day to walk and stop in all sorts of places and see all sorts of things. Kiev is very walkable and you can, if you like to walk, cover all the major sites by foot quite easily. We didn't go to the market, but others did. We saw several churches, monuments, especially the huge WWII statue/museum.
Hope this helps - enjoy a great trip. We hope to do the Kiev to Odessa trip one day - a chance to see more of this area of the world.