I gave it a try because my leftover resin went bad a while back and I couldn't bring myself to buy more for such small projects. Resin won't chemically bond to plastics, though the mechanical bond is usually strong enough for non-structural repairs. I haven't tested, but I'm pretty sure the ABS cement has a stronger bond.
It's about the same viscosity as fiberglass resin; maybe a little bit thinner. It would ooze through if the crack was large enough and you used enough. My approach was to tack the pieces or cracks together with the cement first, then reinforce with the glass and cement. I had good luck using a toothpick to fill in cracks and gouges, too.
Also, unlike resin which is chemically catalyzed, this stuff is solvent based and will start to thicken almost immediately. You also can't glop it on too thick or the outside will set and it'll take forever for the rest of the solvent to evaporate.