Better debugging experience than Common Lisp? Are you sure? Do you know what happens when you hit a runtime error in Common Lisp? You get a full backtrace of all the calls that lead to the error, the error code, the error explanation, and THEN a lot of options that you can do to make your code keep working "on the fly", for example the runtime environment will give you the following options:

   0: [KEEP-OLD] Keep symbols already accessible FOO (shadowing others).
   1: [TAKE-NEW] Make newly exposed symbols accessible in FOO, uninterning old ones.
   2: [RESOLVE-CONFLICT] Resolve conflict.
   3: [RETRY] Retry SLIME REPL evaluation request.
   4: [*ABORT] Return to SLIME's top level.
   5: [ABORT] Abort thread (#<THREAD "new-repl-thread" RUNNING {10060E47B3}>)