Played both with Epigoni and RotA. Like Epigoni a bit more but that may be mainly because it was the first mod I played (and I played it a lot). Both mods really change different things. RotA fills the map with nations (no more uncolonized countries) and in many ways makes the gameplay much more challenging. I recall that once, while playing Macedonia, I got very annoyed at Carthage taking over Epirus next door, so I clicked the "support rebels" button. To my amazement, not the usual three peasants with pitchforks but a 20k stack of rebels proceeded to remove the Carthaginians from the premises as well as ravage my lands once they were done. End result was indeed a comeback for Epirus. RotA somehow makes your decisions have much more dramatic effects. There are some downsides though. Somehow there is a lack of women at least when playing a monarchy and this persists for quite a long time, so a lot of promising characters would never get married.
Epigoni doesn't touch the basic gameplay so much but changes the map all the more, so all kinds of minor Greek city states (Elis, Cyzicus, Boeotia, etc.) are there. Ideal if you want to play like for example the historical Antigonus Gonatas and not obliterate everything in sight, but dominate the Hellens with lots of alliances and vassal contracts.
Like Lucaluca, I've hardly had a problem with CTDs once I turned off autosaves.