These are kind of extreme for binoculars. Each lens is almost 5 inches in diameter. 20 power also means the field of view is somewhat limited compared to ordinary 7 or 10 power binoculars. Plenty of power and light-gathering ability; perfect for comet finding.
Are you sure, RW? I can't remember the last time I heard of someone discovering a comet with 7 power binocs. A lot more people are doing it, nowadays. So by the time you could pick it up with smaller binoculars like those, chances are someone else with better optics would've already found it.