Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
Is the DiamondMax 10 300GB 16meg cache all that? Would it be good for my primary HD? Would there be any performance gains in photoshop compared to a 7200rpm 8meg cache HD?
Quite possibly a performance gain; its higher density means higher STR, and they don't have as drastic a problem as Seagate does. The 16mb buffer doesn't hurt, either. However, I'd go for the Maxline 3; the warranty is two years longer, for like $10. Buy from zipzoomfly.com for best shipping.