We've used Brake Buddy for 15 years. Over all those years, we've had two vehicles set up as toads, so a portable brake made sense. If we had only one toad, I'd want something that didn't need that In-and-Out.
Brake Buddy, however, isn't installation-free. There's a breakaway switch, and in nearly every installation, it's better to install a dedicated power outlet wired direct to toad battery with adequate wire and fuse. It's minimal, but I've still had to do that on four toads, the two we started with, and the two we have now.
That Ready Brute system also needs minimal installation, but beyond that, the braking is all in the tow bar so it can serve multiple toads.
If I was choosing now, I'd go Ready Brute, even if I had to get the apply cable installed professionally.