Nice question, thank you. I did not have to work with 6.5, because at the place of my employment we did not use SQL Server until, according to Microsoft developers, last line of Sybase code was removed from the product (thus giving birth to 100 percent Microsoft SQL Server 7 and initiating the party to celebrate the event). What I find amazing is that it is still easy to find some documentation about it. Here is the quote from TechNet Library -> TechNet Archive -> The Mole: Inside Microsoft -> The Mole # 5:
Yes, yes, yes, you can apply Microsoft SQL Server 6.5 Service Pack 5 to the Microsoft Small Business Server to make it fully Y2K compliant. While versions of SQL Server 6.5 SP2, SP3, and SP4 are compliant with minor issues, SP5 should provide complete adherence to our Y2K standards. This being the case, you can tell your clients a dumb joke (A man walked into a bar. Ouch!) Or simply urge them to have a nice day.
Oleg