Hunters discussing Unit S15 in Colorado highlight the area's challenging terrain and the importance of being physically prepared for steep hikes and unpredictable weather. They praise the unit for its healthy population of trophy-size animals, but emphasize the need to thoroughly understand the area's draw odds as they can be competitive. A common suggestion is to scout the area prior to the hunting season to identify key movement patterns and locate favorable vantage points. Overall, the sentiment is positive, with experienced hunters recommending early planning and preparation to successfully navigate and hunt in Unit S15.