From what I can tell, they are just using standard instruction trace rather than a full trace, so they can only inspect execution history rather than full data

From what I can tell, they are just using standard instruction trace rather than a full trace, so they can only inspect execution history rather than full data history that most other time travel debugging solutions provide. The advantages of their approach of just using the standard hardware instruction trace functionality is that it functions even on shared-memory multithreaded applications at "full" speed unlike most other time travel debugging solutions. The disadvantages being that it requires higher storage bandwidth, Intel does not seem to support data trace, and even if it did support data trace would require significantly more storage bandwidth (something like 10x-100x).