2.13ghz x 2 for one thing, and for another, now a days, you get more work per cycle. The 6600 outperforms literally ALL AMD chips before they started releasing all these newer updated versions. the 6420 now performs near it. Sucks to be AMD. Buy a chip for $200 bucks from Intel, or pay $999 for the same performing chip from AMD... The 6000+ AMD X2 chips (new tech) can barely hang with the Pentium EE 965 (3.7ghz w/ older tech).
Anyways....
Cases, it's appealing, it's just that I used to own a computer shop, and got the same cases, and other cooler ones for a fraction of that price. Were talking about $200 cases at Fry's, that costs to them $20 bucks to buy. I bought cases to sell at the store from our vendor for $10 bucks with 450w pw, same as Fry's that they sell for $100+. I keep our system in a nice cooled box under the console. Isolated. Except for my play system, which has a cool looking case that cost me $30 bucks and is a screamer, nice and cool inside at 20-25c.