LW (I have LW6) is really great system, for coding, experimenting, and the CAPI user interface is platform-independent (almost, there are some differences, but you can handle them).

I do use MSVC all the time at work, XCode occasionally at home, and have used Delphi quite a lot before my current work.

But I also bought Lispworks Mac/Win32 versions, and I feel much more productive there. Why? Because I have listener, I can quickly recompile the current buffer (Ctrl+Shift+B), or the current enclosing function (Ctrl+Shift+C), or if I'm at the end of expression evaluate it (Alt+X E).

I can keep recompiling the buffer, and all variables declared with defvar would retain their values, I can change object definitions on the fly.

It's just easier to experiment.

Weaknesses - I'm so much used to the MSVC debugging (I Actually used to be Turbo Debugger junkie in the past), that I miss that - it's simply not easy to debug in LW (or EMACS + slime + any other lisp).

But do I need to debug that much more? No - I don't, but that could be because I'm yet at the amateur level.