I switched from Fusion 2 part to All for Reef about 3 weeks ago just to simplify things. It's early still but growth has been great and colors seem better too, but again it's early still so I hate to attribute it only to that just yet. I only run a 20g tank though so I don't go through too much, up to 8mL daily dosed via pump overnight on an SPS heavy tank. Ask me again in 3 months lol
For me, I always struggled balancing the Alk and Ca properly. I would get my number I wanted and go for that, not necessarily what was "balanced." All for Reef makes it so I don't have to worry about that as much. I have dosed Fusion2 I think once, small amount to boost Alk when I first started while it was getting in the system. But other than that it's held solid at 420-440 CA and 8.0-8.4 dKH. Something to note, the bottle tells you to adjust dosing according to Alk. The Tropic Marin guy on here actually stated it's easier to monitor it by Calcium as that is in the water column immediately, where as the Alk is delivered differently so you don't see a measurable impact in the tank right away. That's why when I switched, I helped boost the Alk once the first few days while it got established.