Hi Ola,
It might not be a good option to open client to users in between ,there might be inconsistencies.
Please check tablespaces and make sure they are enough and check if update stats has been run
did you select the option of parallel processing before starting the client copy.
In SCCL ->Go to->Parallel Process->you have an option to define maximum no of process which can be used .This will speed up the copy.
But in your case as copy is already started this might not help,just a point to note for next copies
Regards,
Murali