Add new D6 web server to R5 environment?

We have an R5 environment. I am installing a new (additional) web server in the next week (we already have an existing R5 web/mail server). I’m wondering if it would be safe/recommended to install Domino6 on the new web server right away, and make it the first D6 server in our environment.

I’ve read the “Upgrading to Lotus Notes and Domino 6” redbook, and they recommend that the first server you upgrade to D6 be your adminstrative server. In my situation, this would not be the case.

I’m wondering if anyone could offer some advice about whether this is a requirement for a trouble-free D6/R5 co-existence environment, or only a suggestion?

So, is it a good idea to add the new web server as D6, or should I just install it with R5 and wait to go to D6 until we’re ready to upgrade our main production (administration) server first?