Interesting choices, man. The Wahoo Elemnt MIni can operate without a phone, but that's not your intent. The Cateye Padrone has the larger display, but Wahoo offers the very cool out front mount for the Mini. For the second bike, the Mini defaults to the phone's GPS, no speed sensor needed. Also, for cadence, just use the Wahoo Cadence sensor and attach it to your cleat for dual bike use. In short, if you just get one each Wahoo cadence and HR strap, from what I see you don't need anything else no matter which device you buy. As far as auto sensing two different bikes, you'd likely need two speed sensors. Also, you'll probably still need to hit start and stop with both if you want the trip logged. Note: I don't own either one, but I do use Wahoo cadence/hr sensors. Tough decision.