I had a C50 for2 years. It was a huge move from the S40. After a couple of weeks I got used to the larger size and weight. For longer hiway trips it was way more comfy. The extra weight made for a stabler ride, especially in the wind.  It was a bit under powered for 2 up riding and above 70 mph it was getting close to its top end. Other than these 2 issues I really enjoyed the bike. When the wife decided she enjoyed riding with me I got a c90. Even bigger but way more power and  more stable on the hiway.  All these bike are great, it just depend on the type of riding you want to do.