My two 2x2 GB Mushkin kits use Powerchips.
My G.Skill 2x2 GB kit uses Powerchips.
The only good clocking Micron in 2x2 GB kits right now is the one you bought, which thus far has shown very promising results.
There is D9HNL in other 2 GB dimms, but it's horrible for overclocking.
All the other high clocking 2 GB dimms use Powerchips presently.
Keep in mind it's not the same ICs as in the 2x1 GB kits, which are 90nm ICs [D9GMH/X].
All the newer Crucial [that uses Micron] is 78nm, & clocking is worse thus far with that on the 2x1 GB kits.
2x2 GB is different story though, as the only Micron that was used much in 2 GB dimms prior to the unknown IC in the kit you ordered was what Mushkin used on their older 2x2 GB kits, D9GSV.
I'm not such a fan of Micron as i used to be though, since it seems to be more prone to premature death than the other ICs out there.
And i see people posting on forums all over that because Micron owns Crucial, Crucial is always Micron...which isn't true.
While it's usually true on their high end, they've used lots of different non-Micron on their lower end over the years.