All of the most recent generation Sweets have their Pro Clear (clear coat) over the paint so they will all break in pretty tacky. Also, Roots has pretty sticky paint as well, I just don’t care for their kens as much. The silk paints that KendamaUSA, and others, use is nice too. Not sticky but not slick either.
Also, if you really want something nice, get an RWB (www.rwbmfg.com). Made in USA and they also make Grain Theory kendamas.
Strange, but a couple of days ago I was practicing Kendama and thinking how it would be a great low impact (almost no impact) exercise for people recovering from knee or back injuries. Because we use our legs so much in the throw while keeping our back straight Kendama could be used as a recovery exercise.