All GUI OFM-s I've seen missed the main (IMO) feature of Midnight Commander: seamless integration with the plain shell. In MC I can select files with Ins/*, then run command with %t macro to process selected files, then press Ctrl+o and look to the shell output, then maybe run some other shell commands in the full-screen mode, then press Ctrl+o again and return to the dual-panel mode. Moreover, I can edit shell script with the embedded editor (F4), then press Ctrl+o, run the script, read the output, press Ctrl+o and edit the script if needed.