I have a Jem77BFP and a PGM300 (and previously had a Jem7DBK).
Tone can be disputed- they're both pretty different toneally. The BFP and DBK are both a bit warmer and rounder, while I find the PGM300 has a lot of nice crunch to it (TZ in the bridge), and is a bit thinner sounding overall (even in the neck position). Just want to say that's not a bad thing- just different. Personally, I feel the PGM's sound just 'rocks' more, where the Jem is more of a beast for multiple applications.
The necks are quite a bit different, too. The PGM's is much thinner than the Jem77BFP's, and not far off from the DBK's 'Super Wizard'. It's a great feel! But then again, I like Ultra necks too, so... well, there you go. It's definately a neck that makes you feel you can play fast.
In the looks department, I love my PGM300. Love those f-holes. And the way the volume knob is out of the way is simply awesome! I find myself hitting the volume knob on the Jem more now since I'm used to just flailing on the PGM. Scalloped frets? I never saw any use for them, other than the tone compensation thing. Up on 21-24, you can't really dig in anyhow, so they're only cosmetic to me.
Bottom line, if I had to choose between the BFP and the PGM, I'd go for the PGM. But then I'd curse myself for letting the BFP go. And then I'd kill the guy that made me choose between the two.