samba - Sep 2014 - Scientific Linux (RHEL) 6.5 + samba 3.6.9-164 file locking (oplocks) usage?

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 ...

would be glad for any piece of info,

cheers,