I really like how the chord diagrams are displayed during playback on my iPad version of iReal. I like how they only take up the top half of the screen, & when the song gets halfway down the page, the chord diagram window jumps to the top. This way, you can always see where you're at in the song as it's playing.

But I do not like the way the chord diagrams display during playback on my Mac PowerBook - they're way too big, & the window takes up almost the whole screen. I've tried to resize the window, it won't let me. I thought there was an option for showing Large or Small chord diagrams, but I can't find it now. Have looked in the Help files, Preferences, etc., didn't find any info on this.