My server is a dedicated 2x dual core 3.4GHz Xeon (i.e. 4 cores) 4GB RAM, 200GB 15K RAID 5 with the first official 104 release. I only have 48 users but it looks like the CPU usage is quite intense. It takes 5-10 minutes to receive an email at the moment which is acceptable however I am uncertain of what will happen when more users are added. I've seen in the doco that it is recommended to have multiple servers if you have more than 100-150 users. However I'm not sure if my CPU usage is typical. 3 of the cores hit 100% every few seconds. It looks like a total average of 60%.

What do other people see with there CPU usage?

87.3 3866 root /usr/bin/python /opt/novell/datasync/syncengine/sbin/connectorManager.pyc
22.3 3865 root /usr/bin/python /opt/novell/datasync/syncengine/sbin/connectorManager.pyc
20.4 3564 root /usr/bin/X :0 -br -verbose -auth /var/run/gdm/auth-for-gdm-H02G5P/database -nolisten tcp vt7
20.0 4562 adminten gnome-system-monitor

Also FYI I have found times it would take more than 30 minutes to synchronise emails. On both occasions the source of the problem was when the server requested data but did not get anything and therefore kept asking. This happened to me once with a "ghost account" i.e. requests were being made for an account that was not a user on the datasync server, this was because of old gweventnotification keys on the account (Thanks to Peter Cajka from tech support for finding that one)
Also I added an external entity that was also the server's address book user, don't know which part of that it had a problem with but after I added it, usage got higher and response got much worse.