I've had the Billet SC1 a little over a year now and just went with the SC2 with the internal vents a couple months ago. What can I say other than it's awesome. I'm riding a ktm 380 which are notoriously thirsty bikes. The SC really helped my fuel mileage out. No more fuel anxiety on longer trail rides. The single circuit design is very simple and gives the bike a very linear powercurve, with added low end grunt. Corey Dyess of Technology Elevated has really helped with every question/concern I've had with both carbs. The carb is awesome for making huge elevation changes, It's truly a set it and forget it deal.