I don't know anything about PureVia, but I'm on my third container of Truvia (9.8 oz each). When I was still experiencing a lot of Candida symptoms I couldn't find any other sweetener that wouldn't cause reactions from the Candida, that is, until I discovered Truvia. For whatever reason, I've never received a single reaction from it, and I used it all during my protocol. I would suggest you simply test either product if you're interested in using either.
It's Stevia that can actually lower the blood sugar, which can be dangerous for some people.
On the other hand look at this:
pure Sugar registers 60 on the glycemic index, xylitol is somewhere between 8 and 13 depending on the source of the xylitol, sorbitol is 9, and both Stevia and Erythritol register 0.