Well...as someone who's had one of these types of devices for a while (Aerostick), I have to say that what will "make or break" any of these products is how the data is transmitted off of the device AND software being available to take advantage of the data. Right now, for me it's a bit of a PITA, which discourages me somewhat from playing around with it.

That said, it's interesting that the SwissSide unit has 2 pitots, one that appears to be just for 0 yaw pressure, and the top "split" one for yaw angle determination. That's something the Aerostick actually has on one unit (i.e. 3 ports on one "tip"). It appears that the Argon unit only has a single port, and thus just no yaw measurement.

I also think the location of these devices may cause some inaccuracies, unless they are calibrated after mounting. That's because they both appear to end up near the "stagnation bubble" of the rider, and thus will "under read" the actual apparent wind speed. That can be calibrated out just by going out and measuring apparent wind speed vs. wheel speed on a zero wind day. Even with the tip of my Aerostick mounted such that it's basically aligned with the leading edge of my wheel, I still find that only reads ~96% of ground speed. For example, from some of my early "playing around"...



edit: BTW, the spread in that data shown above is most likely because it WASN'T a zero wind day, and I was doing straight back-and-forth runs to try to get a feel for the calibration.

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