You always want to compare and take the advice of people who are doing what you did. People who have never had 8x SunPower over their acropora think that what they do will scale, but it does not once you get out of frags. One of our locals had 8 units of Gen 4 XR 30s over standard 2x2x6 180g to replace just a 5 foot 8 bulb SunPower - to be fair, he does have more light on the ends now. People who have never used one underestimate the coverage and power of SunPower and also how packed mature acropora systems can be... which is why you see so many add 4x, or more, T5s as their colonies grow... you just gotta have the coverage. They mean well, but just don't know. The Gen 5 does appear to cover better, which is why I said 4 instead of more.
If you do just get 2 of the units, then don't sell your SunPower for 6-8 months until you are sure that you like the cones of higher light, lower spots on the outside and the shadowing. It can work, especially if you strategically place things, but it is not anything like what you have now.