What is wrong with using the built in backup (to workstation) in server manager
Nothing at all, except one thing: manual intervention is required.
I realise it does not have the same feature set as Affa (eg rise feature, & ability to quickly rise a backup server to production status).
Right, this is very attractive. I have used it in the past, e.g. to migrate to new hardware. Workstation backups should work perfectly for that.
For an alternative that is used by sme server professional support personnel, & can backup locally or remotely via ssh, see http://wiki.contribs.org/Rdiff-backup
I simply wasn't aware of Rdiff-backup up to now. I have used Affa since a long time... Keep also in mind that I started this thread asking for recommendations

A 'must have' for me was to have a second machine making fully automated remote backups each and every day without any manual intervention over a VPN network connection, using hard links for rolling backups. Affa is capable for all that. Rdiff-backup probably too...
Then you ought to convince the developer to bring out his baby to the light and set up a wiki page on this topic. If it is not yet possible, then you should help arnaud to finish that contrib (test, development, ....)
Absolutely. I have been in touch with Arnaud directly, but I guess he is currently out on holidays. (So I will be in a few days.) I have tested Affa 3 quite a bit, and I posted my experiences and detailed steps in the bug tracker. Unfortunately I am not capable to build RPM packages, so this needs to be left e.g. to Arnaud. I would be happy to transfer my steps from the bug tracker e.g. into the Wiki. I have never done this before in the SME forum (I have used Wikis elsewhere), but why not start with a HowTo on Affa 3!?
Regards, turandot