I totally understand, it takes a while to approve those segments.
😞I think it's a cleaner way to go about certain campaigns. Ex: I use territory segments for assignment rules.
Also, you can easily report on certain segmentations(
http://community.marketo.com/MarketoTutorial?id=kA250000000Kz0w). And I am hopefully going to take advantage of the dynamic content and snippets soon so that's a biggy.
If you have time, I'd just try making a few segmentations and seei what you can do with them. I still use smart lists for a lot of stuff but I find segments helpful in different ways. There is a deep dive about segmentations too.