to bi-wire or not?

It is entirely speaker / system dependent.....full stop.

without taking a bi-wire loom for an A-B in-house bake-off, you will never know if a bi-wire is an improvement or a marketing o,scebo. Otherwise, all the blind responses herein are nothing more than anecdotal with no assurance that it will actually work in your system.

So ask your dealer for a weekend loaner for the cables and put it the litmus test,  with the understanding that if you do change, he gets the sale (don't stiff him by then buggering off to the used ads in AGON)

Also depends on the quality of your existing jumpers. If they aren’t up to the task, then you may hear benefits from bi-wiring but it will have more to do with the removal of the poor quality jumpers from the chain than the act of bi-wiring itself.

+1 akg.  Very speaker dependent.  I have compared single vs. shotgun biwire Satoris on my Soliloquy 6.2s and prefer the biwire, but the difference is not night and day.  On my cables, the high frequency cable is a standard Satori cable and the midwoof cable is specifically designed for that purpose -- not sure how much that is driving the difference between bi and single wire.  I believe Robert at AZ will custom build a shotgun pair for your specific purposes and speakers, but you might want to check on that.  If you're in the NYC area you're welcome to borrow mine for a bit.  

What actually made a bigger improvement than biwiring was adding thin wire jumpers in the banana connectors ALONG WITH biwiring (this was recommended to me by a cable designer that I tried with great skepticism).  This tightened the bass up noticeably and improved imaging to the point that I wouldn't listen without them.  I got mine a while back from Stereovox (now Black Cat?), and IME this is a cheap (and relatively obscure) tweak everyone should try if they can.  

Anyway, hope this helps and best of luck.  BTW, great speakers.  Ironically my final decision was between my 6.2s and the RM22s, and it was a VERY tough decision.  My next speakers will almost certainly be JAs. 

Richard Vandersteen is a proponent for bi-wiring, but as akg points out, it is speaker dependent.
But, if the speaker manufacturer made the speakers bi-wire-able, then they probably should be.
I think your dealer should be able to provide a loaner pair for you to try, too.
B