Upgrade to BOE XI 3.1 SP3 from BOE XI R2 FP3

We are currently on BOE XI R2 FP3.3 distributed across 3 physical servers and intend to upgrade to R3.1 SP3 ending up on those same 3 servers (This is a requirement). I have done a lot of reading in the upgrade guide and I had pretty much decided upon a side by side installation by imaging our current
environment onto VM server(s), and installing 3.1 onto our current prod servers and then I read these paragraphs in the Upgrade Guide:
"In a complex upgrade, you install a new deployment of BusinessObjects
Enterprise XI 3.1, either on the same computer as your previous
BusinessObjects Enterprise deployment or on another computer. You can
copy the data from your previous deployment to the new one.

After BusinessObjects Enterprise XI 3.1 is installed, both deployments can
run at the same time. You can uninstall your XI or XI Release 2 deployment when you are ready to do so."

So, does anyone here have experience with a side by side upgrade on the same servers as the R2 installation? Does it work out allright? Obviously, I will be creating all new objects for CMS database, auditing database and repository. How do I need to set up the web server part of the
installation?
Thanks for your advice.

Rick