From the studies and what I've read no sweeteners in general comes in first place. After that Stevia (although many don't advocate it) comes in second. In general any sweet taste to your mouth, is going to cause a production of insulin, it just depends how much insulin and how much of a blood sugar raise. Depending on how much insulin is produced, this could make you more hungry throughout the day, even if you do not consciously note it.
On a side note, I've been doing low-carb a long time, and it was not until I switched to full-primal and ditched all sweeteners except one packet of stevia in the coffee I have 2-3 times a week, that I really noticed how much I don't need it. On top of that, everyone is gonna have their vices in any lifestyle, if that means using stevia so you stick to being primal in other areas (ie working out, eating healthy, having fun...) than no need to throw out the stevia.