[Hebdomad]

I've not looked at Scheme and I doubt that I will due its minimalist nature.

I've had no conceptual problems moving from a C/C++/Java/Python/Ruby over to Common Lisp. I've not found the functional basis that different. I actually don't think it is that different. You pass parameters to procedures to gain results, and you do the same with functions. The terminology is a bit tricky as well, especially both function and procedure are used interchangeably.