Ok... pacrom in a few words...
Well, basically, its a different operating system for a GP32 put simply (compare Win2K and XP).
Pacrom doesn't look quite as nice, and it doesn't have a built in MP3 player, BUT it lets you run .fxe files from anywhere on the Smartmedia card (not just in the GPMM directory)... and, more importantly, it lets you ignore the need for the freeloader - which saves a LOT of time.
And it doesn't have the animation on startup, of course, so its quicker.
Only problem is you need to be careful when you put it on, because if you get it wrong, it completely messes up your GP32 to the extent that you have to pay a LOT to get it fixed (ask ph0x, he's the most recent person I know who's killed it and got it working again).
If you want to send it over, do two things...
1) Make absolutely certain that the version you're sending is 0.31, not 0.2 - 0.2 does not have PC-Link support, so you need to mess about a lot to get anything into the card.
2) Have an AC adapter and batteries...
3) Get someone to do a checksum compare on the file you downloaded with one they've got that they know is right
It'll probably work, but its the small probability that it won't where the problem lies - to give you an idea, I flashed mine the day after I got it on nearly-new batteries and had no problems. Phox did it some time after with new batteries or an adapter and ran into problems - its basically random (so far as I can tell) how much grief it gives you. Thank God mine didn't die on me.
Some programs still need to use the freeloader to run (Omsk's TG16 emu, as an example), but most don't - and its possible... JUST possible... that GPVGP requires that you aren't using it...