1 Rig with 4 GPUs or 2 Rigs with 2 GPUs?

[madmartyk]

I have 2 more R9 280x's on the way.  The question is, should I put them into my existing rig (would need a bigger PS) or build a 2nd rig?  I have the parts for rig #2.  Pros vs Cons?

Some I can think of are:
With 2 rigs I can mine 2 different coins
With 2 rigs I can have them in 2 different locations (not blowing a breaker)

With 1 rig I would get a kick ass hash rate.

Thoughs from the experts here?

Thanks!!!