Though many readers have reported the problems with Safari 4.x on Leopard, few of the same issues were reproducible by testers/developers and sources who have hands-on access to the latest post-WWDC builds (10a380 and later) of Snow Leopard.
We’ve noted the considerable boost to Safari 4 performance that users of Mac OS X 10.6 build 10a380 have experienced in previous posts to our Twitter feed, and it would appear that a similar difference applies to many of the stability problems readers have been reporting with 10.5.x, even after the recent Safari 4.0.1 Update is applied.
In fact, in several cases, it would appear that v4.0.1 actually made some of these issues worse. Paradoxically, though the 4.0.1 Update package is not available for Snow Leopard (requires 10.5.7) and 10.6 is still almost three months away from release with plenty of system-level bugs left to be fixed, virtually all testers we talked to were left scratching their heads in surprise when attempts were made to reproduce the widely reported crashes/misbehavior on 10a380 or more recent builds. Read more