Asus DVD-E616A or DVD-E616P3?

I haven’t been able to find a site that does a review of both drives and I’m trying to see if there is any difference between these two drives besides the cache (the A has 2 megs where as the P3 only has 512k). The purpose of this drive is for an HTPC so whats the most importatnt to me is relative noise when spinning at slower speeds, performance for watching movies, and ability to read a variety of disks (types as well as quality).

The Asuses seem to rate pretty well in the these categories from what I can tell and Newegg has both drives for relatively the same price. It seemed smart for me to go with the one with more cache, you know, for read-error protection, but I was trying to figure out if these drives have any other difference. They seem to have almost the exact same specs, sans the cache, but they are different at least to the point of having different firmware with different version numbers.

Can anyone shed some light on this? Thanks!