These both make cold brew, but are pretty different products.
Here's how they work:
Toddy Brew System
The Toddy system makes what you can think of as a coffee concentrate, which is best cut with milk or water to serve. So it's great if you enjoy iced coffee with milk, since it makes a strong cold-brewed coffee that stands up well to milk. The Toddy also has the capacity to make a large batch, about 36-38oz of coffee concentrate. We recommend this method if you'd like to brew our New Orleans-style Iced Coffee at home; the Cold Brew Bottle is not well-suited for this recipe. You can read more about this product on the company's website.
Hario Cold Brew Bottle and Hario Cold Brew Pitcher
The Hario Cold Brew Bottle and Hario Cold Brew Pitcher, on the other hand, both produce a ready-to-drink iced coffee that's a bit more delicate and tealike.
It also has a much smaller yield, about 20oz of brewed coffee. It's super convenient and a bit less of a production to use than the Toddy system, and has a reusable filter so you never need to purchase new filters. This is a great option if you are looking to make just a few servings of iced coffee with minimal fuss.