There are a couple of reasons you might do this, the first is an exploit.
The second is potential locking and corruption issues with legacy flat-file databases. There is a performance penalty in doing this - but how noticeable is it? What other reasons are there for not disabling SMB2 (assuming the security vulnerability is fixed) ?
"The second is potential locking and corruption issues with legacy flat-file databases." Please explain this issue a little bit more, e.g. what do you mean with flat-file databases? thx ice
I would not disable SMB2. The only reason would be the flat-file databases which Microsoft doesn't recommend to use in the future.
If the application-client resides on a XP or W2K3 there is no SMB2 in action, even if the flat-file is stored on W2K8.