I have had the 06099M WiFi Display with my 06059M Atlas Sensor for three days.
I've got a ticket opened up with tech support right now because I have extremely intermittent connection to the data via the MyAcurite App. The app may report my sensor being offline for 5+ hours, then it works for 10 minutes. It's arbitrary, so it may be more than IP addresses jumping about. That said, the only thing I have not yet done is reserve a static IP address (which I will try next).
I think the Atlas is reporting reliably to the Display WiFi because when I connect again, I think it serves up all the graph data from when I could not connect. However, seeing the data points are in clusters of 5 or so with fairly large gaps between them, I'm not certain now. I'm no familiar enough yet to know if that is how it is supposed to work. Plus, I know my internet works because I have a Revo camera system I can see those feeds even when the weather station is "offline".
I have it reporting to acurite and also put the wunderground access key in the setup but it never reported to wunderground. I deleted that sensor on wunderground so now I think I have to go through the set up again and put the new key in. I wonder if it didn't report to wunderground because I haven't installed backup batteries in the display yet.