Personally unless you run stereo FOH, not much point.
I've stayed mono as I prefer a tighter focused sound but that's personal preference, considering the relative cost, why not
Hey V8 !
I will definitely go stereo (fake one), you need 2 Kempers for a real one, BUT the effects in stereo .. in my opinion is totally a different univers and approach... and to be honest the HeadRush is so small and light than having two will be so easy !
Stereo front and monitors