Oh yes! I love this topic point

I purchased both brands of UV sterilizers just to test out which one had the best response rate and positive impact. I plumbed the pentair high output 80 watt uv and 57 watt aqua uv into my reefer 625XXL. The pentair is a beast and takes up considerably more space but works better to be honest. I believe the pentair contact time with the bulb is really what makes this unit more superior in performance.
I tested each unit by taking one uv sterilizer offline for a 4 week period after both units were running together for a 2 full month period. I went offline with the pentair first and saw a noticeable impact on water clarity and algae build up. Within 2 weeks of turning the pentair sterilizer back on I was happy to see improvement. I turned my aqua uv off for 30 days and was pleasantly surprised how well the pentair did its job.
Flow rates are really managed by us and is determined on what your trying to accomplish. I am running the flow rates 150-300 gallons per hour to be effective against protozoa. One key ingredient on this subject matter is size. You definitely want to purchase a uv sterilizer that 3-4 x the suggested water volume of your aquarium for considerable impact.
Hope this helps!