Focusrite Scarlett 18i20 4th Gen

Who it's for:
For anyone who needs to record a lot of channels at once, like a full drum kit or an entire band. It's a rack interface aimed at more complete home studios and bigger recording sessions.
What stands out:
It has its own driver through Focusrite Control 2, with stable, low-latency performance on Windows, plus remote control of the preamps from your phone or tablet, which is really handy in a studio setup.
You get 8 mic preamps, more transparent and with more gain than the previous generation, along with 2 instrument inputs on the front and 8 line inputs on the back. Auto Gain sets the level of all 8 channels at once, and Clip Safe automatically protects your take if the signal gets too hot.
Air now has two modes: Presence, which adds brightness and presence to the signal, and Presence + Harmonic Drive, which adds midrange harmonics for more character.
There's built-in talkback to talk to the musicians in the live room, and switching between two pairs of monitors so you can compare mixes.
It's expandable over ADAT with up to 16 extra channels, plus 2 more via S/PDIF, for when you need to grow.
It comes with Ableton Live Lite or Pro Tools Intro and the Hitmaker Expansion bundle, with plugins for recording, mixing and mastering.
What's missing:
It's a rack interface for a fixed studio, not something you carry around. And it's a bit pricey for what it offers compared to some competitors in the same range.
Summary:
The 4th Gen brought real improvements over the 3rd Gen: cleaner preamps, Auto Gain across all 8 channels, Clip Safe, two Air modes and remote control from your phone. A solid choice if you need lots of channels at professional quality.