Let me get on my soap box for a minute. (I have worked in radio for over 20 years, so I think I can speak on the subject.)
In a 2-man booth, the job of the Play-by-play announcer is to describe the action, and update the game situation (score, time remaining, # of fouls, etc.) The color man is supposed to analyze and comment on the action. One of my gripes with Grimm is that he tries to be his own color man - let the color man do his job. And he complains about the officiating way too much. If there's a call that directly impacts the game, let the color man comment on it.
As far as preparing for games, I'll let you in on a little secret - it's actually easier to prepare for a pro game or a D-1 college game -because those teams have full-time media relations people who provide game notes, stats, info, and access to coaches and players for interviews. Yes, you still have to do your preparation, but it's a lot easier preparing when other people feed you the information. Teams also publish media guides, with player profiles and tons of background information. By comparison, I think it's actually tougher to call a high school game when you don't have access to the same level of information - plus, it's a heck of a lot easier to call a game in good facilities, as compared to a high school pressbox, or a gym where you may be sitting next to some bratty little kid.
I will admit that Grimm is a better PBP guy than Dave Lee - but that's damning with faint praise in my book.
