DE Stubby has only flown with the pilot. I've done fast taxis with a passenger on board and lifted off slightly, but the field we operate from is not conducive to test flying - too much "progress" in the area. It seems that it should fly OK, though.
We hope to get to a larger field with open spaces around to gradually add weight to the passenger seat to finally answer this.
Stubby is heavy, with too much panel, a full accessory engine and a stout main gear. All useful at times. If building again, I would build the airplane lighter. Forego the "nice" stuff, be real selective. Probably shave off 50-100 lbs.