Hi Adam,
FWIW, I had the same problem when I switched to AR sessions. After researching and finding many suggested solutions, I found one that worked for me. I discovered that I was storing some large objects in my sessions. I changed my technique to only store the object ID of the larger objects and my "dropped connections" problem ceased. Of course there is the added overhead of having to "re-find" the object as needed, but for me at least this was a minor inconvenience. Anyway, my persisted session data hovers around 300 bytes.
Kendall