Laptop You seem to have it, except you have to get out of the vertical mindset and get into the horizontal.
Aroons show TREND not rise. As you say, the longer the two stay at the top/bottom the longer the PPs rise/fall will occur. The only time a trend is signaled, is when one indicator is at the top (over 70)(the trend) and the other is at the bottom (30). Anything between is showing direction.
Both together shows indecision (No trend) high or low, but something must happen, PPs won't stay flat for ever. If they move together from bottom or top, it shows accumulation on "expected" reversal. If one changes before the other, it shows weakening or strengthening of which will win the "expected" reversal.
As for cross points, what I've read doesn't say the aroon will predict size of pop, but I've noticed as you, that the lower the cross, the higher the original pop.
I think that's because when they cross below 30, both indicators show weakness and if it's high, strength. So depending where they cross, shows the amount of resistance to the reversal.
http://www.investorshub.com/boards/board.asp?board_id=3972 Welcome to my mind! 
