Well the E-170works with both custom panel and the default panel.
And Andrew niether had i heard about FPA before i tried it the first time, having no clue what it was, and why the plane didn't do what I expected it to do.
The flight path angel allows you to select a certain climg or decent profile like 3,5degrees, very handsome to use if you need to make a approach at an certain dencent angle Like to EGLC or LOWI on the VOR/LOC approach. So you won't need to figure out wich FPM setting would be correct.
Just read the charts and put the angel in there:%
just make sure you start at the right altitude..... Tried that and not to recomend.
Hope you don't loose the interest for flying ProPilot, and good luck with the E-170