both parks are pretty decent. kb remodeled their park this year (got new rails, painted features, added a new park, got an airbag). the jumps at kb aren't that good though. always have icy or carved out landings and there are always people standing on the knuckles and on the landings. the only problems with kb are they dont move features once they set them up, they only maintain the jumps and rails at the main park (by the end of the year there were small jumps that turned into rollers and rails that weren't maintained to a point where the kicker on to them just turned into a pile of snow) and it takes a while for the main park to open. personally, i loved kbs park this year, and imo it had a ton of fun features.
the parks are pretty sick at holiday valley too. they have a sick main park, and the features are moved around on a regular basis. they have sick features, and they get creative with their setups. they have pretty good jumps, and they can be hit in a line without having to speed check too much. the only thing about holiday valley thats bad is there is always a lift line for the park lift, or at least on weekends there is one. at kb, you can lap the main park fast (theres a double that only services the terrain park and one other trail). on a good day, you can get in 2 or 3 runs in 10 minutes.
i personally am at kb more than holiday valley (kb is 40 minutes closer to me). im there 2 or 3 times a week usually. i go to holiday valley on weekends about every other week. so ill be around for sure.