With regards to performance, Craig Chambers's thesis on the Just-In-Time compiler for Self proves pretty definitively that a language as (or more) flexible as Smalltalk can be very performant without losing any dynamic properties. It certainly isn't an easy compiler/runtime to recreate for any given language, but it does exist.
It didn't exist at the time you're referring to however, so in that context the point does stand, mostly. I believe there was some form of flexible compiled optimization for Smalltalk (since Chambers's thesis references it as prior work) but I forget when that was and how commonly used it was.
That sounds about right. (Just to clarify, what I was referring to with "did not exist at the time" was specifically Self's JIT and its new techniques.)
It didn't exist at the time you're referring to however, so in that context the point does stand, mostly. I believe there was some form of flexible compiled optimization for Smalltalk (since Chambers's thesis references it as prior work) but I forget when that was and how commonly used it was.