We are currently using datastream 7i, but our upgrade path was a little different.
We started in 1995 in the good old dos days with Rapier (Europe). The Y2K syndrome forced an upgrade. At that time Rapier was bought by Datastream and they launched MP5. Rapier at that time was a huge system running on Oracle and Datastream fit it in a Windows jacket. The MP2 system was a file based system (running on paradox), while Rapier was a full blown Client-Server RDBMS.
In short MP5 was the Client-Server generation of Datastream.
Last year we upgraded to Datastream7i, and the big feature was web-enabled, that is what the i stands for.
I don't know Datastream 6.0, but if it also a client-server system, I suspect it must not be too difficult.
On the other hand, from MP-2 to Datastream7i will be a culture shock if you are acustomed to systems like paradox and access.

Regards

By the way, someone knows how to attach a pdf to a Purchase Requisition so the supplier can get additional info, without I have to e-mail everything to our Procurement Department. ICT is still busy studying the possibilities....