What key factors to be considered for a mixed domino servers environment?

Hi there,I have a multiple Domino servers setp as follows

Server1 - First server - Release 5.0.9

Server2 - Additional server - Release 5.0.9

Server3 - Additional server - Release 5.0.9

(It is not a cluster environment)

Now I need to setup another additional server, but as a partitioned server installation which we are intending to install with Relase 6.5.1, just would like to know is there any one out there who have tried mixed environments, and any key factors to be considered.

Thanks

Subject: What key factors to be considered for a mixed domino servers environment?

The replication Settings ! for the design