OK, we need a more formatted reporting system here, if we are going to be able to determine if the firmware fix works or not.
First, when you post your screen shots of poorly performing drives, or drives suspected to be effected by the issue, post the following data as well.
1. Is the OS installed on the drive, if yes, what OS, and how old is the install.
2. Do you have Antivirus software running at the time of testing. if so, what AV software?
3. What chipset model and manufacturer is controlling the SATA interface, and what driver version?
4. If another SSD is active in the system, does an actual realtime file copy from the problem drive exhibit the problem?
5. If possible, monitor and record the drive temps while benching, as well as other temps in the sub system (CPU and motherboard).
6. Post S.M.A.R.T data using something like HDD Scan.
7. Number of background applications and services in task manager, and any CPU intensive processes, CPU utilization during testing.
Hopefully this will allow some corrilation of data to allow an underlying cause to be discovered.