I just switched to pedals (Favero Assioma Duo) after being a powertab hub user for about 10 years. Love 'em. I do highly recommend.
The ptap is a great product that met my needs for a long time. I switched b/c I wanted to ride with power using race wheels on my time trial bike, be able to more easily swap the meter between differently configured bikes, and just enjoy some nicer wheels for my daily driver training bike (Giant TCR).
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"Your beauty is an aeroplane;
so high, my heart cannot bear the strain." -A.C. Jobim, Triste