The thing that grosses me out when I attempt to do that is then the polymer filling stuff gets all wet and nasty. That stuff just weirds me out...
Our twins are currently just breastfed, which means their poop is basically yogurt. So nothing to dump in the toilet yet. I remember we would dump the harder poops out before we threw the diapers away if we were out of town and using disposables.
Worth pointing out that just because you use disposables doesn't mean you can't rinse it out / dump into a toilet. We used cloth for 8 months and then transitioned to a daycare that wouldn't let us use them. I still dump all solids into the toilet because I don't want my baby's room to smell like poop 24/7.
Also, if you read the box, most diapers will instruct you that you are supposed to do this, as human waste doesn't belong in landfills.