Would there by any downside to getting the update, just to be safe? I would think not, but just curious.
this software update will change some of the transmission's shift characteristics. as long as you can live with the consequences, there will be no downside.
back in 2006, many SRT8 owners insisted on getting the latest flash for their NAG1 transmission. most were happy with the results but several were quite pissed that they could no longer hold a gear past redline.
if you are not experiencing the symptoms described in the TSB, I suggest you wait until those that need and get the update post about their experiences/likes/dislikes of new transmission behaviour. then, you can make up your mind whether or not you're willing to live with it.
back in 2006, we were able to revert back to older flash versions for those that were disappointed. unfortunately, that is no longer an option. there is no going back.