It's crap irony (or sheer unbelievable value
for money) but £10/$10 stuff like Magix
Music have BPM adjustment tools which are the
best and easiest to use in the business.
If I have to use Audition to re-BMP my prefered
method is Effects/Stretch/Ratio, and then some
slight adjustments within the mixer window; it's
finicky as hell, but made easy by having a simple
drum beat generator: load up your desired BMP,
bang out a 4/4 beat and then record a few bars into
Audition to sync up to. I use Hammerhead and/or
Fruityloops, but there's hundreds of free drum
loop generators out there.
I refuse to use any version of Audition
above 1.5.1, so I'm uncertain if there's been
more populist stuff (like BPM tools) added to
CS2 or 3.