This article is from the Macintosh system software FAQ, by Elliotte Harold firstname.lastname@example.org with numerous contributions by others.
Officially if you don't have a Quadra or PowerBook, you don't
need System 7.0.1. Unofficially some changes were made that speed
up SANE (numerics) operations on 32-bit clean Macintoshes with a
floating-point coprocessor. These include all IIci's and IIfx's plus
LC's and IIsi's that have had a coprocessor specially installed.
(Neither of the latter machines ships with a coprocessor.) See