I have a Sol and get signal loss once or twice a dive. It's only for a few seconds and so doesn't inconvenience me... but I am curious about the upgraded transmitter. When did they switch? I wonder if it is possible to upgrade for a reasonable fee--I use the buddy monitor feature too, and that definitely doesn't work as well as I'd like, being very sensitive to range and orientation.
Dont bother. I have the newer style transmitter, which takes that weird battery. My wrist and transmitter are back at Scubapro for your same reason. Was advised by LDS that it will probably take a few weeks to get it back. A buddy of mine has owned his Luna for over two years and dives like a maniac. His units (his and his daughter) have not had a single issue.