We just started using tooth soap this past month. So far, I think it works just fine. To answer your q's about pros and cons, well, the pros are that it's all natural, a little goes a long way, your mouth feels clean, they are easy to travel with, a container of tooth soap will last a long time. We got ours from Rose of Sharon Acres, I believe.
As for the cons, it does seem "soapy" at first. Depending on which flavor you choose will dictate how "clean" your mouth feels. We have Lemon Ginger and Orange Cinnamon - taste wise, they are fine, but if you're used to peppermint or spearmint from conventional toothpaste, then the peppermint or spearmint tooth soap might work better. I tried the peppermint and it does seem to give that minty feel I am used to from the dentist. I think you just have to convince yourself that your mouth and gums are clean, even if they don't feel "minty", lol, assuming you try a non-minty flavor. Oh, as for the aftertaste, well there is a little bit of one so of course if you eat something right away after brushing, that might not taste so good but it would be the same with regular toothpaste, too
I say go for it!