I always run one solid, one flashing. The flashing one gets attention, the solid one gives depth perception and hopefully breaks up the blinking light fixation problem.

In my case both are superflashes. However, one used to be a TL-LD1000 which was dimmer, and I used it on constant. However, that was mainly because the Superflash's flash mode was so much better.

That would be my opinion; use the superflash in the mode that it excels at; flashing. If you're not comfortable with the brightness of the other one, buy another superflash