TCL 9 brought some welcome string improvements, and things run faster overall. But in my case, it's hard to say how well that's actually played out, partly because I haven't done the work to find out. My TCL scripts and apps work well enough to allow me to be lazy about them.

Performance is up, but so is my inertia. So while TCL 9 could be transformative, for now it remains a white paper I've skimmed, not a revolution I've implemented.

I think TCL does an opaque thing, everything "is" a string, but if you don't use it as a string, it's actually stored in some optimized format. Then it converts back to a string on demand

I still prefer Lua personally. Their type system is easy for me to understand