Powerlet, the American company, were the first to offer the new, thinner, electric jacket liners with their Rapid Fire liner. The others like Warm’n’safe / Keiss and now seemingly Gerbing (with their Micro WirePRO jacket liner) have joined the gang. They are all very good, though Powerlet have dropped much of their range on offer.
The tricks I think are:
A. Remove the standard winter liner from the jacket to reduce bulk
B. Find a good way to control the heat properly. I use Powerlet’s dual wireless temperature regulator, so that I can control the heat of the jacket liner and my glove liners separately. As the jacket and gloves are so efficient, it is useful to be able to control the heat efficiently.
For very cold days (for example -5 C all day in the Ardennes) I have Powerlet’s electric trousers liners and socks. All excellent and each controllable separately from each other and separately from the jacket and gloves, via a second wireless controller. A prefect set-up. Was it cheap, no. But as I was doing lots and lots of miles, worth it.
Would I go back to an electric vest? No, I don’t think so.
PS I saw the Keiss jacket in post #21 a week or so ago in Infinity, Holborn. It looks very good. The new Gerbing offerings arrive (in London at least) towards the end of the month. I am pretty sure either would work with my Powerlet controllers, so would do as a replacement should my RapidFire kit pack up.