Well, tastes in programming languages differ from person to person of course; you may as well ask what makes Ada better or worse than Pascal or Algol68 and Rust

Well, tastes in programming languages differ from person to person of course; you may as well ask what makes Ada better or worse than Pascal or Algol68 and Rust. I personally am very fond of the strong support SBCL has for type checking, which is something I find many Lisp-inspired languages just don't seem to care about. Every programming language has its strengths and weaknesses, S-expression based languages are no exception, though what I consider a weakness in a language someone else may consider a strength. Things that come to mind immediately are CL's case insensitivity (Ricardo Signes' talk A Million Billion Squiggly Characters touches on the problems with case insensitiveness), Clojure's decision to randomly use square brackets for expressions that have no need for them (this is one thing I know that other people are fans of), and Bel's streams operating on bits (as in 1/8th of a byte). Though what got me to try CL in the first place was someone mentioning that SBCL is fast, and given that it is still a GCed language, it really is. With Scheme I was bouncing back and forth between Scheme and C because I was unsatisfied with the performance, but with CL I don't feel a need to use C as it is fast enough.