A main issue with the default timing on keyframing though is that loong distances ar soooo slow and small steps too fast. Unless you place keys on equal distances you will get wildly different speeds with small and big distances between keys requireing post editing of the time stamps.
My experience with ENS is quite opposite. If I add keyframes without setting a time stamp ENS is doing very well with keeping constant speed.. Differences can be relative to Your position in model. When viewing from a far (everything seems slow) and from up close (all seems fast even though both speeds are same).. Use time stamps where You want to change the speed only..