> I thought the conventional wisdom was to avoid the stock pre-amp on any recorder ...
People should know better than to make such broad, general statements. The built-in preamps in a recording device may not be the very quietest possible, but if you use high-output condenser microphones, the background noise level of most recording venues will override the noise of most mike preamps. And microphones themselves have an inherent noise which often exceeds the noise levels of preamps at least in some parts of the audio range.
In practice the biggest risk with built-in preamps in consumer and "semi-pro" recording equipment isn't noise--it's that they may not be able to handle the signal levels that your microphones will put out when picking up high sound pressure levels. The preamps then "clip" (distort severely). If you must use a recording device whose mike inputs can't handle the full output of your microphones, overload can usually be prevented with resistive pads at the inputs of said device.
Other problems often found in second-rate mike preamps include incorrect or inadequate phantom powering, and susceptibility to interference either due to unbalanced inputs or "pin 1" problems, which are very common in portable, semi-pro gear.
I happen to have tested an HD-P2's phantom powering ability at an AES convention a few years back, and it seemed quite good. I didn't do any other tests on the preamps, though.
--best regards