When looking for a cheap audio interface with lots of inputs and outputs, you'll be hard pressed to find an interface with as many features as this interface for the same money. with 18 inputs and 20 outputs, some analog and some digital, this interface is great for driving multi-speaker setups.
The preamps are adequate and add relatively little noise when compared to earlier generations of the 18i20.
There are many options for routing audio through this interface, all of this can be tweaked using the Focusrite Control software. Unfortunately, this software is a bit quirky and unreliable at best, with your settings sometimes resetting for apparently no real reason. You'll need this software for most settings, as there are very few physical controls on the unit itself. I don't consider this a problem myself, but it can be frustrating when the software doesn't work as intended. Overall I recommend this interface for those who want a decent multi-output interface on a budget.