Went down to Motolegends, Guildford and bought the Warm’n’Safe heated base layer. I already have a spare dual controller / receiver.
Back home, I can look at the schmutter more carefully.
1. It fits well, with my long sleeved merino layer beneath.
2. It is cut to a very good length, meaning that it will tuck comfortably and well into my trousers.
3. The wire heating elements extend across the rib cage at the front, across the lower back and kidneys at the rear and, sort of, down to T-shirt length on the sleeves. All good.
4. It all seems nicely made, so quality control is OK. I know it works, as I tried it in the shop.
Happy enough so far. I just need to wire it up to my spare receiver / wireless controller, which I’ll do at my leisure.
If you are going out all day in the cold, it will probably suit best. Of though, yiu are only popping out, stopping, walking about and riding home, the conventional heated liner, might be better perhaps. Why? You stop, take the liner off and stuff it somewhere, saving you overheating. That is easier, perhaps, than a base layer?