College hitters: Kingery, Haseley, Bohm, Vierling - looks pretty OK.
College pitchers: Howard, Seabold, Eastman - two out of three are on the IL... but, pitchers.
HS hitters: Randolph, Williams, Moniak, Stobbe - eh. It may simply be too early on the HS players; Randolph, Moniak, Williams are all in AA, and none is dominating. Stobbe is in A-ball, and either injured or playing himself out of professional baseball.
HS pitchers: Gowdy: Again, injured. I mean, he's pitching now, but he's missed beaucoup development time. Pitchers.
General comments: You would expect college players from recent drafts to be performing at higher levels, and mostly they are. You would expect a higher overall hit-rate on college draftees than HS draftees, because they're more developed/mature at time of draft, so there's less failure risk. Early performance on these guys seems to support these expectations.
All things being equal - Your best bet to get a valuable player, statistically, looks to be with a college hitter. Some HS players, and/or college pitchers, will turn out better, but the odds aren't so good - pitchers at all levels because they get hurt, and HS hitters because there's a lot of development needed, which may or may not occur.