That's a tough question, Mike.

If you move them further away from the wall, the soundstage and imaging may improve but the bass will weaken. If you have a sub, you may want to move them out as much as possible. There's also the dreaded ceiling reflection to consider so you should experiment with what sounds best.

I have mine moved out about 9" (which is the maximum distance I can afford) and they sound divine.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated