Instead of using a vague term like "power", perhaps the LISP fans should promote the concept "leverage", whereby you can talk about getting a task done with the fewest words of code. Small LISP programs can be incredibly clever, and transformation languages like LISP and FORTH are well known to win every program-shortness contest. However Assembler has always been more powerful in the sense that you can do things in Assembler that you can't do in higher level languages, because there is no direct mapping from a higher level language to many of the special instructions that exist on modern chips. So using "power" is a lamentable word choice. LISP does have problems though, many consider it a "write-only" language which transfers very poorly to other programmers. You can measure transferability of a codebase by assigning a new person to it, giving them a task, and seeing how long it takes, and how much is broken in the process. LISP is avoided by most large companies for this reason alone. Leverage and other factors are heavily outweighed in overall cost to the organization by the difficulty of transferring a code base among people.