I'm a long time user of UltraEdit for Windows and was happy to see a version for Linux. But obviously UEx is a much more robust editor than the basic gedit, kate or whatever default editor you have in your Linux install. It takes much longer to start. If set as the default text editor that can be a drag.
No problem. Use AllTray to launch UEx at startup and let it sit in your system tray. Use a keystroke to call it up and the response is instantaneous. You'll probably usually want UEx minimized to the tray, so double-clicking a file to load it into UEx then means you'll have to also use the keystroke to recall UEx from the tray. But it works nicely. Since UEx naturally handles multiple files in tabs, you just doubleclick all the files you want to open, then use the keystroke to recall UEx from the tray. Very snappy.
Note that by default AllTray captures the close-window function, so clicking the X doesn't close the app but instead puts it back in the tray. That applies to the X in the tabs also. Can't use it to close tabs, so you need to use ctrl-w to close tabs.
The speed increase is well worth it if you want to use UEx as your default text editor.
I use the command "alltray -k Control:10 -g 1080x850+160+100 -l -st -stask uex" at startup. Note that the -k option uses keycodes, so in this case I use cntr-1 to recall UEx. Run xev in a terminal to tell you the keycodes is need be.