I really feel like this post belongs here - this IS NOT a Xenium, and it functions differently, but it is extremely inexpensive, and MAY be viable alternative to the DuoX2/Aladdin as a chip to install for your customers, if its problems are not an issue, or if you install a switch as explained below...
The chip DOES NOT function the same as the original, as I mentioned, and can not be considered of the same quality/funciton set. I installed it on my 1.6b. It came with a blank 1 meg AMD EEPROM, and the Xenium 2.0 prereleash flashed. Install is easy - just the LPC with the D0 point, as there isn't SUPOSSED to be a need to turn off the chip as it is meant to boot the retail bios.
HOWEVER the first problem I encountered is with this very option. The I set up the first boot option from the TSOP, and named it Retail via the Xenium OS. I attempted to boot the stock bios, but the Xbox turned itself off and rebooted back to the Xenium OS, so I can't boot the retail bios... Maybe there is some way to fix this, but as I see it, you'd need to install an external switch - more trouble than it's worth for most.
I managed to then flash the new X2 (internal release) 512k bios. There is an option for the color on the LED. You are supposed to be able to select a different color for each bios, but it appears that the clone only has a pink light on it. So this function is unavailable on the clone.
The other issue is ACT2 - anti clone technology 2 - which is supposed to disable the chip eventually... I havn't been able to find any claims of this occurring, but I'm probably going to run this chip for a few months to see if it actually does crap out. I'll let ya know if it does :-P
The price on this chip is probably about $12-$24USD on this clone. I got it for $12 I'm pretty sure - a damn good deal, if you ask me