After seeing some responses from the Notes/Domino community complaining about the apparent lack of testing I thought I'd better do some clarification.
Although I come from a long background in Notes with mult-server environments, I'm currently enjoying something of a break while I get the early child-rearing period of my life completed. I'm now at a small business with only ONE production server an no need to worry about screwing up other people's systems. If anyone has to wear the blame for a problem - it's me.
That said, we're doing things here that I've never seen done at any of my previous (and much larger notes/domino installations). We have some business/industry critical stuff running on Domino and it's being used by most of the biggest names in Australian banking.
We have a backup server which does nothing and could be down for weeks without anyone noticing. I always upgrade this first. We're soon going to be moving to a cluster - where I'll have to be more careful of future upgrades - but until then... anything goes.
I'm not a fast mover with upgrades, we've only been on XP for 2.5 years, and I still have one WinNT server (our PDC). I'm not forging ahead with Active Directory because it still has yet to earn my trust.
After doing every major and every minor upgrade of Notes/Domino without ANY issues since R5, Notes/Domino has well and truly earned my trust. I can't say that about any other software in my long history in the computing industry.
Our Notes/Domino DRP is so well developed that - well, secretly I suppose I want it to fail so that I can prove it to management. Well... no, I don't really want it to fail - but I think you get the idea.
Finally - do I rely on IBM's testing? well... Yes and No. I trust that IBM has tested the core components of Notes/Domino (Mail, HTTP, HTTS, SSO etc...) much better than I, with my own meagre resources could do.
I don't trust that any third party applications developed for us, developed by OpenNTF or developed internally have been tested - for obvious reasons.
We have good test plans for post-implementation which really haven't changed all that much from one version of N/D to the next (other than adding new systems and new procedures to the list). If I make it through these tests, then the server has been tested as well as it can be.
The bottom line: Testing and implementation can be VERY quick - provided that you have the right plan, the right backup and the right software.