RHEL 6.5 + samba 3.6.9-164 file locking

Hi,
anyone tried to speed up samba file transfer over the network by turning off the kernel opportunity locking - the so called:
"kernel oplocks = no"

I've read a lot of discussion on this topic and people reported speed up in file transfers as considerable.

Thing is, if "kernel oplocks = no" then any linux process accessing file on the samba share for write access would respect (wouldn't know) that samba client is writing into it, hence file corruption would happen.

But what about scenario, where you have purely data storage filesystem, shared only over Samba and accessed only by windows client workstations - would it be OK to use the "kernel oplocks = no" ?

Also,
i can't find it stated anywhere properly and clearly, if this is global option (which would be bad) or 'per share' option (which would be great for testing ...

glad for any piece of info,

cheers,