Re: mid-range lumia with good camera quality
thanks!
im just canvassing to replace my 620
are those two models the only decent mid ranger lumias out there?
No, there are many "decent" mid-range devices out there. You did however ask about the camera, and the 830 or 640 XL are the only two mid-rangers I'd consider if the camera is your primary interest. Since you specifically mentioned low-light I'd definitely prefer the L830 however, as the L640XL lacks OIS which becomes important in low-light conditions. The L830 and L640XL are compared in the first document I linked to.
Allegedly there is also a Lumia 650 in the pipeline, but as of yet we know almost nothing about it.