Hello,
Did you ever get back to CH 1.28 after checking that 1.30 is slow?
Do you changed any computer equipment, software configuration, ... along with changing CH version?
I don' really see any reason that CH 1.30 should be as much slower as you describe. One major thing that could affect speed is unicode support, however it should not decrease speed 10 times.
What I can recommend:
1. Go back o 1.28 and check if the transfer is still around 300MB/s,
2. Send me the log file and the task files related to the slow task (on mail),
3. Check the CPU load when transferring the data.
Maybe it will clear something up.
Ixen