I've used the Garmin "magnet-less" speed and cadence sensors with my Lezyne Super GPS and the sensors paired and operated as expected. I recently added a PowerTap hub so I've ditched the speed sensor (since wheel revolution data from the PT makes it redundant). I also use an old Garmin HR strap that came with a Forerunner GPS watch.

One note for anyone considering the Garmin "magnet-less" speed sensor ... I have observed strange low/unstable speed readings when crossing some bridges. The problem is not related to the computer (same results on a Garmin, ANT+ enabled phone, and Lezyne) and I suspect has something to do with metal embedded in the roadway. Probably not a big deal for most people, but in Florida riding bridges is the closest some of us get to training hills so this problem was more than just a minor annoyance for me.