Dedoimedo published a review on Raspberry Pi OS with the Plasma desktop environment.
Raspberry Pi OS & Plasma - Troubly McTroublesome
Detailed review of Raspberry Pi OS with the Plasma desktop environment running on Raspberry Pi 4, covering initial setup, look and feel, customization, system responsiveness and performance with and without compositing, video performance, heating, numerous discrepancies and differences from Manjaro KDE 2004, various bugs and problems, and more
Raspberry Pi OS & Plasma - Troubly McTroublesome