So ... obviously, we cannot get too many of Bailey highlights.
I have also seen Flagg play in 2 games this year.
They are not really all that similar STYLE players, other than both being 6'9" or so, athletic, and top 3 ranked. Without making a judgment on who is better, or has more potential, no judgm,ent here:
Flagg is much more of a "polished" player, generally a better handle, more traditional post-up and pull-up jumper moves - and does GREAT with those moves, FYI - great creating space for himself, etc., a better (more fundamentally sound) defender, the "look" of a power rebounder.
Bailey, on the other hand ... He is visibly more explosive athletically, and IMO much more fluid and smooth with how he moves with the ball, and a significantly more CREATIVE shot-maker ... but when you look at his highlights, just vs Merrimack, notice that on almost every shot, no matter how acrobatic, or seemingly out of control, how he gets his SHOULDERS square with the rim -- on EVERY shot. He can be fading away, (like on that ridiculous 20' turnaround fadeaway), or the step-back 3, or as he several times wove around inside the lane to get short or medium jump shots ... In EVERY example, he gets his shoulders square to the rim, which shows remarkably consistent body control, no matter where his feet are. And Bailey rebounds just fine, FYI.