I actually had it implemented that way originally, with the transaction work happening as a part of the other actions inside the rest client and not counting towards the duration.  I ended up changing over to treating them as "real" actions since the commit/rollback operations include validation and other steps that would normally happen during the ingest/delete/etc action, and therefore are a major part of the over all execution time of the work you're trying to benchmark.  The commit time seems to range from 20-40% of the action time, depending on how many commits are involved.  It also simplified the structure some and cut down on synchronizing.  I can definitely see your point though, and I'm open to being talk back into the other approach