I do, but other prefer using attached

but then ... sometime you have

    if attached foo then 
... this is ok


and sometime you have

    if not attached bar then

and that hurts my eyes ;)
so we end up sometime having

if attached foo and bar = Void then

personally I prefer avoiding mixing thoses
so
if foo /= Void and bar = Void then

...
so this is really a matter of taste (and not using the  "not attached bar" ... which is hard to distinguish from "attached bar" )