> None of the GPL Lisps compare to what is offered by the likes of Allegro Common Lisp and similar environments.

Care to elaborate?

Allegro Common Lisp, Franz Lisp provide IDE tooling reminiscent of the Lisp Machines. With visual debuggers, graphical REPL, hypertext documentation triggered from the REPL, libraries to integrate with the OS....

Additionally their optimising compilers are quite good.

Didn't realize, the only LISP I regularly interact with is emacs lisp...