As someone who has tried a Heated Santi BZ400 and was ready to buy one, I was not impressed. I ended up going with a Rofos BZ400 and a Lola Q-vest (XXL for 2 extra heating panels). Candidly I do work for a company that sells these items, but I genuinely believe its a much better solution, as do many of our customers after demo-ing the two. It's a more flexible solution, as the undergarment will wear out before the heated vest, and allows you to mix and match layers for the environment. It's also significantly cheaper, at just over $650 for the suit and vest. That being said, a 90W heated vest definitely needs a Pitkin/heat controller otherwise you will be sweating and flipping the switch very often (found that one out the hard way LOL).