All this chatter has left me a little confused... what are the options available for us mainly drysuit divers then?
I used to have a wireless Thermulation and unfortunately it was one of their lemons (from the early days) that had many problems and although it was taken back and repaired under warranty several times (I had to pay for the couriers back and forth from Canada - so that wasn't fun), I lost faith in this product somewhat. I eventually ended up trading it back for their wired version after I couldn't handle paying to send it back yet again (they credited me the difference in price).
I still use the wired version under my drysuit (and with a wetsuit while on vacation), but this means that I can only use it on boat dives when I turn it on before splashing and turn it off after back on the boat. It's inconvenient to not be able to use my heated vest for shore dives, which is the majority of my diving.
I haven't been interested in the Santi heated vest option or DUI heated suit, both of them due to the size/weight of the external battery. What appealed to me most about the Thermulation initially was the small size of the batteries. I was thinking about buying another wireless Thermulation, now that the bugs have been worked out, but I see here on this thread that there may soon be other options?