Never used the replay utility except about a year ago when it just came out to analyze the GOTM results. Actually, it helped to improve a lot! I was positive that starting from patch 1.22 of C3C, the utilities have been essentially fixed regarding the multiplayer. But iirc, in version 1.15 of C3C, it was quite possible to open the saves with it without password.
The only real thing people might consider using is MapStat. And seems that all MP bugs have been essentially fixed there. But you never know.
