Well, I could probably even level faster solo if I wanted to, I'm just slow these days at upping the difficulty. I have bosses off for my WS and PB, and they're still at 0x0. Running tips, there's not much reason to run at a higher setting (an argument could even be made for going -1x0). Do five tips, hop on next toon. Though now that I have Eclipse with decent slotting, I'll probably up it on the WS.
My Elec/Sonic is at least on x2 if not x3. Synaptic Overload works just as well on large groups, after all.