Exophase
Nothing good will ever come of Exophase.
I know that benchmark performance doesn't always equate to real world perforamnce but It looks like the gpu makes quite a difference in benchmarks, I found this review on AnandTech and it shows the SGX540 has about 3x the graphical power of the SGX530.
Of course, it makes a big difference in 3D benchmarks, which are almost never CPU limited. Pandora doesn't have a whole lot of games that do serious OpenGL ES work, so you'll have to ask yourself how much that matters to you.
BTW, not sure if you're saying this, but DM3730 doesn't have an SGX540, it's the same SGX540 as in OMAP3530, just with a (much) higher clock speed. It should still be almost 2x faster in most cases (but still much slower than what you'll find in most phones a year or newer)