Actually, I like having 2 identical setups...you have a backup (assuming you backup semi-regularly), and if something goes wrong, you just swap them out.Anyway, i personally would do something different with it...i find that having two computers set up completely identically is boring...you need to have some variety.
Then, when you feel like living on the bleeding edge, you can go ahead with minimal fears of losing everything...I'm talking about everything from installing weird extensions to putting in a larger hard drive, etc.