Yeah even the Cooper merc ballasts were pretty good from what i've heard. I wish these were made in other wattages besides 70 thoguh. Maybe make it in 35, 50, 70, and 100w.
Not really all that possible unless you remote ballast it. If Niall posts a pics of the insides, you'll see exactly why... The ballast is held in by a pressure bracket similar to what AEL uses and if the ballast is any taller than the one in there, it won't screw down. If the ballast is any wider, the ignitor would have no place to go. If it was and bigger coil wise, the socket would have no room. This fixture seems to only hold those crammed little 120v NPF HPS ballasts. There are mounting screws for a mogul base socket in there too, but i believe you'd need a different reflector...... you can see part of the ballast bracket holder sticking out of the light....
But also yeah, A CWA ballast probably won't fit in this, because the 70 watt HPS ballast is small, and there isn't much room in the thing.