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.
I've used 5870 CF and 5870 and 5850 CF. As far as microstutter I've notice very little. Other then the Call of Duty games, I've had pretty much no microstutter in other titles.
I run CF 5850's and have not noticed any micro stutter but I only play a limited number of games. CF is broken for Black Ops has been since 11.11 I think but for me it's not an issue since I run it in windowed mod so I can alt.tab out to admin the server. Currently running off an OCZ 700W MOD-X-STREAM PRO which so far is handling things ok but I won't be surprised if it dies.
I ran two 5850's for a year and a half and never noticed any signficant microstutter. If it was ever there, it wasn't noticeable to me or enough to be distracting.