Our starting place is similar to Prodigy in that we also see active learning as a key piece of the puzzle but we think to make active learning work reliably really does need taking into account parameter uncertainty. As far as I know Prodigy doesn't do this. We are also working to make our active learning work at the level of batches and be cost-aware. Often the most valuable examples to label for the model are the most time consuming for humans and we work to trade this off.
A few other differences are that we do offer a cloud hosted solution so getting set up is much faster and it's more natural for us to be able to accomodate team annotation and quality assurance. By providing a hosted model we also give you the option of deploying features very quickly and continuing to improve them post deployment.
I'd be curious to know the barriers that Saas introduces for you?