What is the benefit of using segments? From what I can tell, the main benefit is the fact that segments are mutually exclusive within segmentations. However, there's a huge limit on what filters are available within a segment (why is this? it's quite frustrating).
Segmentations are like dynamic static lists, that is, they run faster but are more automated than static lists. Segmentations are required to run Dynamic Content, which is also a huge plus if you go down that route.
Yes, Segmentations run on a waterfall selection method and yes, you cannot use smart list filters or certain behavior filters to build them.
What exactly do you want to do? There is probably a way.