Hi,
This is likely due to Filesystem emulation taking place on the File Server when new files are created.
If for example you were to drag & drop a file onto the File Server via. Explorer.exe, the transaction will probably appear quick since due to caching the transfer window quickly disappears anyways while FS emulation is still taking place.
If your workload however is editing existing files within a MS Office application or saving new files in for example Excel directly to the Fileserver, then the user application hangs until the Check Point agent finishes the emulation and releases the file.