Unsecured. More risk because there is nothing backing it excepted the faith the company can pay.

Like for like then unsecured.

But this may not be the case. If you are comparing an u/s bond from a first class company and a secured bond from a virtually bust company then who knows. The u/s bond may have covenants (like rental income being 3x total loans and the property the other bond is secured on may need re-valuing to current values.