Sometimes you need to test your Flash stuff with different plugin versions. Even if you just want to run some performance tests, it is very useful to switch to the release player (see below for another example). For windows there is a neat Firefox Plugin that makes switching quite a snap. On Mac there is one too – I haven’t tested it, but it’s supposed to work (though I’m not too sure about that when I read these comments here). Still I prefer to work with Safari and I kind of dislike the thought of starting Firefox to just switch Plugins. 
Fortunately I’ve found another solution: WSPluginSwitcher. This one comes as a Cocoa app and once configured (you really should read this wiki page), it works real well for me. Also they have prepared plugin versions for you to download (though the most recents are missing, but no big deal really). As for the speed tests, let me just give you another example (impressing enough for me to wanna switch players for real world testing). In Debug Player:
method...................................................ttl ms...avg ms
tare [2] 0 0.00
CSSFastParser 603 120.60
CSSRegExpParserFast 987 197.40
CSSRegExpParserFastAdvanced 1457 291.40
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In Release Player:
method...................................................ttl ms...avg ms
tare [2] 0 0.00
CSSFastParser 354 70.80
CSSRegExpParserFast 972 194.40
CSSRegExpParserFastAdvanced 1469 293.80
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Both 10.0.22.87, and exported as release swf. Oh, and by the way tested with another useful tool from Grant Skinner: AS3 Performance Testing Harness.