I currently use two RGB controllers: the Falcon F16v2 and AlphaPix 4 v3. Both of these controllers have performed great.
The AlphaPix initially gave me some problems with random flashing, but a recent firmware update resolved this issue.
The AlphaPix can accept 16 universes of data (2,720 pixels) while the F16v2 can accept 64 universes of data (10,880 pixels). The only thing with this is that no power supply can handle this many pixels and certainly you cannot put 600+ nodes in a string without additional power applied. Although I expected to do this, I think that power injection with additional waterproof connectors and wire runs was the biggest additional expense to my whole project. For each 50-75 nodes, I would need to run a separate power wire (30-50 feet in most cases). In my relatively small display of <2000 pixels I have around 2000ft of wire. I could have avoided this by purchasing more power supplies and controllers, but for this year I just injected power.
With the F16v2’s new differential boards, I hope to use them this coming year to both power and provide data to additional props I will be adding. Each board can run up to 1,360 pixels and each power supply can run around 500 pixels. Using these boards I hope to eliminate much of my DC wire runs and put the differential boards closer (or in) some props.