What do you mean about the power going to them being 200w or 125w? Are you considering using different amplification for each pair?
Depending on the receiver/amp, you'll send more power during peaks (depending on the duration of the peak, which nowadays is accepted as 200ms as a good general time for most transients in music). If it's a highly regulated amp, there may be no dynamic headroom, so you should use the RMS rating of the amp as what you can expect max before distortion/clipping. Other amps, you might get 1.5dB to 3dB (40% to 100% more power).
Ideally, both companies would tell you what the peak power handling capability is. Hsu saying up to 250w RMS suggests 500w program, and 1000w peaks, but that doesn't matter if you're not going to feed it that kind of power. Since Hsu is so accessible over the phone, you may want to call them.
You also have to consider that the power handling ratings are more geared towards the threshold at which damage might occur. Since you also care about the quality of the sound, there may be more marked differences between the two speakers.
One would certainly think that having two 5.5" woofers and a 5.5" midrange would allow the speaker to output at higher levels with less distortion.
The horn in the HB-1 isn't a horn-loaded compression driver. It's really a tweeter in a horn. With horn speakers, the limitation isn't so much in the treble, but rather the mid-bass. The displacement of more drivers or at least an 8" can help a lot in that department.
You may want to also look at the eD Cinema 6", the eD Cinema 12", and the CHT Pro-10 speakers. I sure wish one of those made an 8" woofer!
There's also the Electrovoice ZX-1 (link
Here' my list of reference level speakers