My wife and I finally upgraded from our synthetic mummy bags this year and the convert custom has been hands-down the best gear purchase/investment we can remember making in the recent years of working to upgrade our equipment. We have used the bags in MN in August (quick overnight test run in 65F), a 7 day backcountry elk hunt in MT in September (overnights averaged around 25F), and then again in MN for hunting/camping in November (overnights averaged around 20F). I purchased a wide, 0F bag and my wife purchased a regular, -10F bag. In the temperatures we have used them in, they have been absolutely amazing. Lightweight, super-packable and unbelievably warm/comfortable in a variety of temperatures. The versatility in temperature control/comfort of these bags compared to a traditional bag is unbelievable. We have never slept so well and so warm on our adventures!
As others have stated, we have both noted that the lightweight zipper catches the adjacent material somewhat easily, but have not had enough of an issue getting in/out to change our overall review/rating. Highly recommend the convert to anyone looking for a great bag that still maintains the "traditional" sleeping bag feel/experience. Look forward to many years in these bags! Worth every penny.