One major drawback to Astropad is that it relies purely on display mirroring. Wireless performance can be a bit hit and miss, so wired is recommended for serious work or especially busy networks. Astropad relies on a companion app running on your Mac and can connect via USB or wirelessly. Astropad has been optimized for use with the iPad Pro and Apple Pencil, and this is the best way to use the app. You can use the Apple Pencil or simply draw with your finger or a cheap capacitive stylus ( but not a smart third-party stylus). A lack of customization could be frustrating to some users who would prefer more control over the UI or pen pressure settings. There are shortcuts around the outside of the screen that allow you to quickly undo, use modifier keys like Command and Option, and access app-specific shortcuts. Sidecar is well-optimized, reliable, and compatible with supported Macs at a system level.
Drawing is possible using the Apple Pencil in Mac apps that already support stylus input, including Adobe Photoshop and Illustrator. One of the best things about Sidecar is that you can use it as a proper second display, rather than just mirroring what’s on-screen. You’ll also need to be using the same Apple ID on both devices, and be within 30 ft (10 meters) of your Mac for wireless to work. Sidecar with the 2016 MacBook Pro, 2016 MacBook, 2018 MacBook Air, 2017 iMac or 2015 Retina iMac, the iMac Pro, 2018 Mac mini, and 2019 Mac Pro or later. Speaking of the Mac, you’ll need a fairly recent model that’s running macOS Catalina or later. You can use it wirelessly or plug it directly into your Mac using the USB cable that came with it, which means you can power your tablet while you work on it. Since Sidecar is a first-party solution, it generally works very well (especially compared to some third-party alternatives).