What’s good: They are warm surprisingly and don't take too long to heat up. They don't take long to set up either, it's just a simple cable from your battery to a cable that I normally put under my jacket.
What’s Not: After a few weeks they stopped working and haven't since! They are also no good in really cold temperatures (-5). The cables do get annoying and need to be cable tied in place to stop them from flapping about when riding.
Your neighbours will eye you strangely. It’s only really suited to your screen, tank and full fairings – anything else gets a bit too fiddly with a giant muppet mitt on your hand!