In this paper we present a comprehensive timingbased attestation system suitable for typical enterprise use, and evidence of that system's performance. This system, similar to Pioneer [20] but built with relaxed assumptions, successfully detects attacks on code integrity over 10 links of an enterprise network, despite an average of just 1.7% time overhead for the attacker. We also present the first implementation and evaluation of a Trusted Platform Module (TPM) hardware timing-based attestation protocol. We describe the design and results of a set of experiments showing the effectiveness of our timing-based system, thereby providing further evidence of the practicality of timing-based attestation in real-world settings. While system measurement itself is a worthwhile goal, and timing-based attestation systems can provide measurements that are equally as trustworthy as hardware-based attestation systems, we feel that Time Of Check, Time Of Use (TOCTOU) attacks have not received appropriate attention in the literature. To address this topic, we present the three conditions required to execute such an attack, and how past attacks and defenses relate to these conditions.