Changren Yongwrote a review of Quarq Riken AL Power Meter Crank Arms - BB30 on November 13, 2015
Familiarity: I've put it through the wringer
The Quarq Riken AL may be its entry level powermeter but it is just as accurate as its more expensive relatives. You are saving some $$$ for a slightly heavier PM. I have mine installed on my cyclocross bike and so far i have not experienced any problem with it. Quarq's customer support is excellent in providing phone/email support if needed.
One thing to note though. On Quarq's website, the Riken AL is listed as having the Power Balance feature, where you get left/right power balance data on your bike computer. This feature, however, is only available to the Riken AL manufactured very recently. But fear not, Quarq plans to release a newer version of Qalvin which will allow you to turn on the Power Balance feature.