Check out the Mavic Wintech http://www.mavic.com/sites/default/f...tech_USB_0.pdf

I don't think using two discreet systems is very easy, since integrating the data to use in a single viewer is either impossible or difficult.

For example, the Wintech needs the proprietary software to view data, but then cannot export in a .csv format for upload to sites like Training Camp or Training Peaks. Even if it could, the ride data would be a separate file from the data you upload from the iPhone app; there may be some way to merge the data on the computer before uploading to TP, but if so, it's going to be super geeky and tedious, and I've never heard of anyone accomplishing it.

So, if you're looking to view ride data comprehensively, in one program or on one website (e.g. Training Peaks, Garmin Connect, Mapmyride, etc.), you need one device to record stats and GPS. If you're content flipping between two discreet systems to view details on one ride, then it may work for you.

My opinion, thusly, is go all iPhone (via Wahoo, remembering RFLKT lets you keep the phone stashed) or go Garmin or Cycleops or Timex or Ultra Two or Mio. Even a base Garmin 200 will spit out more usable data than trying to work with an iPhone + cycle computer setup, which adds lots of steps without resulting in merged data.