Transaction time has the advantage of being almost universally accepted (+E3), and it has no conflicts with valid time (+E1, +E4, +E7).
Registration time seems to be more straight forward. However, often a time of a particular type is denoted by tx where x is the first letter of the type. As r is commonly used for denoting a relation, adopting registration time creates a conflict (-E2).
Extrinsic time is rarely used (-E3) and has the same disadvantages as intrinsic time. Physical time is used infrequently (-E3) and seems vague (-E8).
Transaction commit time is lengthy (-E2), but more importantly, the name appears to indicate that the transaction time associated with a fact must be identical to the time when that fact is committed to the database, which is an unnecessary restriction (-E8). It is also imprecise (-E9) because the transaction time of a fact in general is a transaction-time element, not a single time instant as implied.