same 3870, just a different branding?...

Just clock speed, price, and accessories (coolers, etc.). That's about it.

yeah forgot about clockspeed, but the only one w/ a significantly different cooler is the GeCube, which has piping, and an apparently bigger fan.

It just looks like these all came off the same assembly line, and got shipped out to different companies to slap on their cooler & brand name
...and most of them are even using the same cooler.

I think that's about how it works. Although, they may just receive the PCB (or chips and have to manufacture the PCB) and have to slap their own cooler on.