This is a good conversation to have now!
I just got the Tourmaster Synergy 2.0 vest. It uses up to 48 watts. I don't know if it's built to a higher standard than the original Synergy, but, time will tell. It looks well built. I would happily buy Tourmaster gear over and over because their customer service is great.
Previously I put in the EB PC8 power panel and have the one headlamp kill switch, and therefore the headlight, running on its own circuit. Although I've only run the vest for a couple of days, I've not noticed any power draw concerns with both lights or highbeams on at the same time as the vest.
Another way around the power draw issue is to use battery powered equipment. I use battery heated gloves and they do a great job. There would not be enough use for an all-day ride, but for my commute of under two hours each way, I can keep them charged and running. I use Gerbings built battery powered gloves and love them. So, I've got both brands.
As other comments say, you can add heated gear incrementally. You'll probably find that some step along the way before you get to the full monte that you're warm enough. Wear decent insulated gear and a vest may keep everything warm since your body will be circulating heat. Most brands make systems that daisy chain together. For the Synergy 2.0 for example, I made only one power connection to the relay panel. Then, I could wire the full kit (gloves, pants, vest, insoles, etc...) by plugging one device to another - instructions for this are included with the kit.
Once you go heated I don't think you go back 8-)
We're all here, 'cause we're not all there
Last edited by MrNobody; 11-01-2013 at 02:18 PM.
Reason: clarify wiring info