The office just sprung for a new iphone 6 and I'm considering getting the RFLKT as I can add cadence and heart rate to my 1 device. Right now I have a garmin 605 I picked up for about $100 practically new. I can connect it to my pc and download / upload routes etc, but the only drawback is it doesn't support ant so I wear a separate HR monitor watch and there is no cadence support at all.

Trying to stay on budget and it looks like the RFLKT with cadence is $140. If I went this route I would then have to spend $60 on a new HR monitor, but could use the phone for routes, calories burned etc etc. Would I also have to purchase a speed sensor?

Also on the music side how load does the RFLKT play music? Could I hear it in traffic?