Since the VR (I) already claims a 1 stop gain over the non-VR version, does that mean the VR-II is effectively claiming a total of 2 stops over the non-VR 18-55mm?
Just keep in mind that there is such a thing as sales-talk and another called reality. My cam can shoot at 25600 ISO too but in reality, that's advertisement ISO. It sounds better than it looks.
The same is true for 3 stops VR. Sure it'll have sharp shots but only if... and if...
On a 55mm they can get away with those claims a bit easier. For that length I'd pick the sharpest/widest and would ignore VR. If it's included; fine but a sharper lens without I'd still prioritize. If that's the VR II, pick that one. If it's not, I'd not bother too much about the loss of some VR stop.