You also need a bridging module for the G1 amps whereas the later generations come with a mono switch that inverts one of channels for you.
ETA:
Stereo Stats
50 per channel @ 4 ohms
100 per channel @ 2 ohms
200 per channel @ 1 ohm
400 per channel @ 1/2 ohm
Mono stats:
200 @ 4 ohms
400 @ 2 ohms
800 @ 1 ohm
Real life stats - I measured output on a HCCA 250 G4 @ 100 watts RMS per channel on a 4 ohm load just prior to clipping with a 50 Hz test tone. The HCCA 225 G5 that I have did 73 watts per channel @ 4 under the same conditions.
The only downside is these amps are HUGE footprint, current hungry, Class AB beasts. At lower ohm loads, expect a HCCA 250 to continuously draw close to 80 amps and heat up like you wouldn't believe. On component the HCCAs are great because they have tons more headroom than most 4 ohm amplifiers with the same power rating.