I use the triangle when wakeboarding and fill the ~300lb kgb. With just one or two people in the boat, I also fill the 750s in the back. If there are more people in the boat, I run the 750s around half full. You have to run a little faster with that much weight. It's clean at 80' at 24.7mph. You can ride at 70' at around 23.0mph.
For surfing if I already have the triangle full, I'll leave it up there. I also fill the kgb and the 750 in the rear on the surf side. The only difference I've noticed with the triangle when surfing is that it will keep the corner of the platform out of the water and keep it from causing the wake to wash a little.