Your flying weights are coming out just right. My heavier CX2 is 225 grams and my lighter one is 195 grams.

Now, I will agree that with stock packs, I only get about 4 - 5 minutes of "real" flight time, The rest is just maintaining a hover and some very basic manuevers.

When I fly with a DN 15C pack or the Xtre,e 18C pack, I get full power throught my 10 minutes of flight. I never fly longer than that on a pack.