In December 2020 Google released the new IDE for Google Apps Script. Here is an overview of some cool features as it relates to Sheets scripting.

• You can always revert with the “Use legacy editor” button
• Triggers and Executions are in the left sidebar, rather than a separate window
• Logs appear in the same window in realtime
• Function autocomplete and tooltips are built in
• Function folding keeps the screen cleaner
• All occurrences of a variable can be easily changed
• The definition and references to a variable can be found easily
• The properties service is not as accessible, but can still be used and found programmatically, or by reverting temporarily to the legacy editor