Awesome, macmall is great too. Yep Samsung, 5400RPM.
Actually, its the same drive I installed in my MacMini for a fusion drive set-up.
http://www.newegg.com/Product/Product.aspx?Item=N82E16822152291
Oh so it's installed in your buffalo, but then you installed it in your Mac mini too? The one that comes with the mini stack (seagate barracuda 7200rpm) is good too, right? I got that to run all my backups on.