I have the C-10 ltd. Great speaker! I love ribbons (having owned Apogees, Genesis and Selah line arrays) and the Piega ribbons are some of the finest out there. Very natural, open and airy sound, neutral, transparent and fast. Strings sing. The coaxial planar ribbon mid/ tweeter is very coherent to these ears. Voices are extraordinary.
Yes, the Piegas like power and current. I've had best results with modified Tact amps and the Aloia (not a lot of watts but decent current and a great synergy). They need some space or absorption to the sides, in which case they don't sound bright, just lots of natural detail and superb detail.