Honestly, I think the only full REPL I ever really used was with a BASIC dialect on Atari ST, so I can't tell you what "a real REPL" is. With LISP and Python I'm only a beginner.

But having to type "x " or "p " each time does in no way compare to the direct feedback of the Python or Ruby command prompt, which I heavily envy.

Immediate try-and-error experimenting is also very beginner friendly, and I don't see why we should loose fresh blood because of such an (IMHO) easy to realize feature.

It took me very long to find out how to use the perldebugger as a shell and now I can't understand why there is no automatic x or p !?!