I am not sure I'd characterize the XPA-5 as "more powerful" than the Outlaw 7125 that is in the same price range, let alone characterize it as "much more powerful."
If you look closely at the specs on the 200watt/5channel offerings from Outlaw and Emotiva, they are not even in the same ballpark as far as power supply.
Power transister output devices per channel:
Outlaw 7500 - 12
Emotiva XPA5 - 6
Total Capacitor Capacity:
Outlaw 7500 - 150,000 mf
Emotiva XPA5 - 60,000 mf
Power Transformer (Power Supply) Capacity:
Outlaw 7500 - 2 X 1.6 kVA (3200 kVA) torroidal with independent windings per channel so acts more like monoblocks
Emotiva XPA5 - 1 X 1.2 kVA
125 watts X 7 @ .05% THD (Bench tests have shown this amp to deliver 140+ watts per channel without clipping)
1.6 KVA power supply
140,000 cap supply
6 outputs per channel
The 7125 (7 x 125 watts) has a 1.6 kVA transformer divided into seven channels, which is at least as robust of a power supply as the XPA-5's 1.2 kVA transformer divided into 5 channels. I'd be surprised if the XPA-5 delivered any more real-world power than the 7125.
It might not make a difference to you, but if it does, Outlaw is manufactured by ATI here in the USA (although IIRC some of the component parts come from overseas).