Scaling

Hi all,

I've been doing systems monitoring for a very long time now... I was early on with BB, used HP openview back in day day, blah blah.

Anyway, recently I've been told that in very large installations (multi thousands of devices) things like zabbix are the only thing(s) that will do.

What are the groups thoughts on this?  What ARE the scaling limits of xymon and can they be overcome somehow?