Originally Posted by DoctorOhh
Clever, but there is already a default shortcut
for opening any selected book in calibre's viewer "v".
That works if you only have the books in one format. 'V' won't let you compare specific formats in different records against each other.
Alt-V will, but you have to wait for a dialog box to pop up, then click or select the format you want, then repeat that with the next record.
Mapping a shortcut saves a few mouse clicks or keypresses and is a bit more efficient, especially as I use keyboard macros to make the process faster.