I have the Sena 10 and love it. The only thing I miss is not having FM radio. That said, these things are always improving and getting better like cell phones and PCs. The BlueTooth standard is evolving too. I would be inclined to get the Sena 10 or 20 because of better sound quality and range, improved features, etc. and it won't become technologically obsolete quite so fast. The Sena 5's sound quality, range and connection reliability is not quite up to the 10. The dial on the 10 makes it easy to use while moving and it's easy to play music or dial via voice command or jog dial on helmet. Having the ability to connect with other brands of head sets is important too and a feature you will most likely use a lot. The 10 has better speakers than the 5 and better sound quality for playing mp3's. The best feature of these things though is just being able to converse with other riders while riding.

 

I have the Sena 10 and love it. The only thing I miss is not having FM radio. That said, these things are always improving and getting better like cell phones and PCs. The BlueTooth standard is evolving too. I would be inclined to get the Sena 10 or 20 because of better sound quality and range, improved features, etc. and it won't become technologically obsolete quite so fast. The Sena 5's sound quality, range and connection reliability is not quite up to the 10. The dial on the 10 makes it easy to use while moving and it's easy to play music or dial via voice command or jog dial on helmet. Having the ability to connect with other brands of head sets is important too and a feature you will most likely use a lot. The 10 has better speakers than the 5 and better sound quality for playing mp3's. The best feature of these things though is just being able to converse with other riders while riding.

+1

 

I believe the dial/button interface is more or less the same from the 5 to the 10, and they support the same version of the Bluetooth protocol, but you're not the first to say the 10 has improved speakers, and that in itself might be enough reason for me to go with the 10. My helmet is quite loud and I always wear earplugs, so I want speakers with good fidelity and volume so I'll be able to converse with ease. Thanks for the input!

 

http://www.youtube.com/watch?v=ICjcN9rZuhk

For mounting ease, if you have a FF helmet you want the version with the detached microphone mounted with velcro. If you have an open face or modular helmet you want the version (shown in video) with the attached boom microphone. Cost is almost identical between two versions.