http://bikesmarts.com/4-iphone-andro...nsors-reviews/
Originally Posted by
philbob57
Is there any advantage of one protocol over the other for a recreational rider?
Very few phones support ANT+. Every one of them supports BT.
Other than that, there isn't that much reason to prefer one over the other.
You can get a speed/cadence sensor that supports both.
Blue SC Wireless Speed & Cadence Cycling Sensor | Wahoo Fitness
This looks like the Bontrager ANT+ sensor I use (Wahoo might get it from the same manufacturer. The Bontrager sensor works fine.
Originally Posted by
philbob57
What are the advantages, if any, to using a speed sensor instead of relying on the phone's GPS for speed? (Other than being able to track 'speed' on a trainer....)
If the head-unit has an accurate wheel circumference, the speed sensor (which counts wheel rotations) might be more accurate than GPS for measuring distance traveled. Wheel-sensor based speed is also more accurate (especially, for rapid changes in speed).
Originally Posted by
philbob57
Are there any budget sensors that work well - no freezes, easy setup, fast response, durable?
It seems these cost $50-60 (who knows if that is within what you mean by "budget").
I'd investigate (research) the Wahoo sensor I linked to above. Wahoo seems to be a reputable and smart company (IMO).