We have had 2 class C's and both had problems leaking in the front. My sister and her husband bought a brand new Class C and kept it in a garage except when they were out camping. After 2 years, he had to tear the front cap out completely and rebuild it. He did a nice job.
We live in our Class A, but we bought a small motorhome for Alaska. It is a B+. The coach itself is built like a box and there is a fiberglas cap attached to the front to deflect wind/rain. Never a leak in that one.
Dale