RX100 and High ISO

Hello. First post in this forum — I am typically in the Fuji forum, relating to my X100 and XP1.

I gave my charming wife an RX100 for Christmas, replacing her S100. She is not a photographer, and would be happy enough with her iPhone 5 if not for me. I push her.

She left for her Missouri and her family (don't ask) right after our gift exchange, so I didn't have much time to get her ready for the RX100. I did set up a eyefi card with her iPad, though.

Anyway, I was alarmed by a comment at the front of this site, with the selection of the RX100 as one of the best small cameras. The comments claimed the camera had really lousy high ISO performance. Now I am not expecting XP1 performance, but I hope the camera is at least as good in poor light as her S100.

Any thoughts? Of course I will do some tests when she returns...