Very nice!
If that still meets your initial requirements, I'd say that's a much nicer solution, yes?
And if you don't want to worry about the bad garbage cleanup of "create_function", you could also pass through a named function like so, I believe...
function callback_func($key, $value) { return ($value < 2 || $value > 70); }
print_r(array_filter_multi($data, $callback_func, null));
I'm not as sure about that. But it should work.
By the way,
? true : false is a redundant statement.