Geldenhuys and Hansen have shown that a kind of ω-automaton known as testing automata can outperform the Büchi automata traditionally used in the automata-theoretic approach to model checking [8]. This work completes their experiments by including a comparison with generalized Büchi automata; by using larger state spaces derived from Petri nets; and by distinguishing violated formulæ (for which testing automata fare better) from verified formulæ (where testing automata are hindered by their two-pass emptiness check).