I've always preferred the version with the enclosed cockpit. It just looks swoopy! Besides, one of my all-time heroes, Gene Schaffer used to design models that had similar fuselage profiles. He told me that he got that idea from the enclosed cockpit Lark after it had been published in Model Airplane News.
Attached are two photos. One is of my version of Charles Mackey's Lark that was built from plans, and the other is of Gene's "Blackbird" (so named by his competitors on the East Coast back in the 1960s; Gene didn't name his planes in those days...) at the 1969 Nats. By the way, I've started construction on a Blackbird for possible use at the Nats and at a future VSC.
Later - Bob Hunt