Where are you from? In the UK I'd say it's uncommon but positive. The abbreviation 'boff' is mildly perjorative, but I haven't heard that since school (i.e. 'gr

Where are you from? In the UK I'd say it's uncommon but positive. The abbreviation 'boff' is mildly perjorative, but I haven't heard that since school (i.e. 'grade school'), I suppose since at some point around puberty it stops being insulting to say someone's clever.