According to the reviews of over 15 sites, and myself (Don't have the full version yet), DBP is an older, less advanced version of FPSC.
FPSC is quite new, and has physics, and a ton others.
With good programs (3dsmax + ms3d, adobe photoshop cs2, ect), you have no boundaries like my fortune cookie says... (Nothing to do with the post, but Its been forever and I still have the paper).
The FPSC has a much better engine. DBP has been said to crash frequently.
In the above, FPSC has the upper hand.
But this is where DBP has a chance.
Does FPSC have the source code available too?
(I Do not know), if not, then DBP has gotten
a step up in a heavy gamble.
It can be further edited.
BUT, if my fortune cookie is correct, you can still create aloot of stuff with FPSC scripting.
Thats just from reviews and stuff.
I wish I was only 3400 years old...