After doing some research I have found that the G05 incorporates the ATJ2127 audio chip.
Would it be possible to run Rockbox on this device, or is the memory insufficient?
Despite its announced compatibilty, the AGPTEK Rocker is a little too expensive for my needs, since I'd primarily use the player in the gym.
After a quick look at the Rockbox buyer's guide the only devices that make sense are Sansa players.
My previous player was the Sansa Clip Zip, which I've had for 3 years, yet I have only recently learned about the existence of Rockbox. (Of course it died three days after I discovered this incredible firmware alternative)
The G05 does everything the Clip Zip does, just better, which is why I chose it.
But after learning about Rockbox I might still exchange it for another Sansa player, if Rockbox is not compatible.