I think the Epirote are FAR more interesting. Actually their inclusion, as well as the addition of the greater parts of the map, are my two favourite things about EB.
The Illyrians ALMOST became a 'faction' before Rome destroyed them. The Epirote were kinda cool for much longer, and existed Just long enough to be a serious force to be reckoned with. I'm so thrilled they're in the game, and even in their prime, Illyrians werent that much stronger than what can be represented by Eleutheroi so they're not even in the top 5 of factions I miss
(the only serious one here being Syracusans - I'm thinking of doing a version of Catos "Ceterum censeo Carthaginem esse delendam" and then end ALL my posts in here, no matter the subject, with "Btw I think EB needs a Syracusan faction" ;P )