I have P10s and the Rowland 201s. I'm very, very happy with the combination. To my ears, it's a very neutral, detailed but not bright nor harsh combination. If you like the P10s, I'd definitely try any of Rowland's ICEpower-based amplifiers.
NB: One of the P10 reviews linked from Piega's website has an impedance curve. While the P10 is a 4 ohm load, I don't recall it dropping below 4 ohms anywhere, and it's a fairly sensitive speaker (~ 90dB/W@1m, if memory serves) so it's not really all that hard of a load to drive. (Alas, said impedance curve didn't mention phase angle, just magnitude)