The Sigma Rox 9.0 bike computer has been available in the U.S. for about a year now. I've had one for just under that time and thought I would discuss some long term impressions of this powerful device.
While it will never have GPS capability, the ROX 9.0 has two things the Garmin 705 will never have: long battery life and temperature readings in tenths of a degree. These two features alone should sway some savvy shoppers to the Sigma device.
Other important advantages over other bike computers: data not lost during the annual battery change; system does not reset when leaving the bike for a coffee break; and night backlighting.
On the down side, the Sigma has this fault: the stopwatch will only display with the speedometer. Although heart rate, altitude, slope, and cadence normally display at all times, this area of the screen is replaced by the back and stop functions in stopwatch mode.
When time trialing, a rider wants to know his heart rate and elapsed time at a single glance. Can't do it with this computer. See the following photos to understand:
Also, I find it quite tough to obtain normal slope summary information on my PC. If the bike is lifted up slightly when taking a rest break, the "min/max" slope and "average" slope values are affected. However, even during a section of a ride with no rest break, average slope is most often reported incorrectly. See the attached zoomed in section of a century with unreasonable average slope (inclination) values:
18% average uphill is not correct. I have reported this error to Sigma months ago. Still waiting for a correction to software.