Trying Haiku for the first time in several years. It remains faster and cleaner than any other modern OS, and I'm excited to see ports of RSSGuard, Remmina, and Qutebrowser. For me, biggest issues affecting casual use are lack of support for VPN, Nextcloud, and Bitwarden. SSH tunneling and web apps for Nextcloud and Bitwarden might get me far enough!
First post from Haiku! Biggest usability issue is that my ThinkPad X200's screen is getting a bit dim. I'm using QuickLaunch as my application launcher. To configure the keyboard shortcut, I tried to set /system/apps/QuickLaunch/QuickLaunch as the application path, but that just opens the enclosing folder. I had to use /boot/system/apps/QuickLaunch/QuickLaunch . Not sure what the distinction is.
Clipdinger is a clipboard manager for Haiku that works great for copying plain text between native apps. Press Alt-Shift-V and Clipdinger opens, then you arrow through the clipboard history or start typing to filter. For non-native apps, the best method I've found is to click on the Deskbar icon, select the desired clipboard, then paste. It also supports sprunge for clipboard sharing.
LibreOffice, Krita, Inkscape, and many other Linux apps run well on Haiku. The UI integrates about as well on Haiku as on macOS. Krita is sluggish on my X200; LibreOffice is surprisingly snappy.