What are the key benefits of the Fuji SL 2.1s lightweight frame and climbing capabilities, and how do these features translate to real-world performance on varied terrain? Specifically, how does the SL 2.1s weight distribution and geometry contribute to its agility and responsiveness, particularly when tackling steep inclines or technical descents? Furthermore, are there any notable trade-offs to consider when prioritizing lightweight and climbing capabilities, such as compromised comfort or stability at higher speeds? How do the SL 2.1s features and design elements, such as its fork and wheelset, work in tandem to deliver a ride that is both efficient and engaging? Lastly, what types of riders or riding styles are best suited to the SL 2.1s unique strengths and characteristics?