I have LC, but think AC should run just as well for street. LC better for racing if you are trying for maximum horsepower. I have run air cooled and liquid cooled 2 strokes for many years, and like the air cooled better because simpler to deal with. My moto "simple is better". If nice S9 AC was available, near to me, I would buy it right now.
My son-n-law has S8 150 and I like to ride my S9 and People 50 2T better. S8 150 is faster and has more torque, but I just like the way 2T's run, more fun IMO and fast enough for where I want to ride. From time to time he will leave me on the 45 and 50 mph roads, so that's a bummer, but on the slower roads I can always stay with him. I haven't tested my S9 with it's latest tune against the S8 150 yet, but suspect I may now have similar top speed. An S9 with BBK may be faster than S8 150.