What Dido is going to be great at is EXPANDING.. rapidly.
Rapidly, perhaps, but not early. I'd say Phoenicia is going to be able to expand mid-game more cheaply than other civs, and possibly settle in tight spaces other civs couldn't safely fit a city into. But not in the early game which is when you really want to be getting Settlers out fast.
I may try delaying an early Settler push for the techs, districts, etc. necessary to get cheaper Settlers to see how it works, but right now I think it will seriously delay getting my empire up and running and likely cost me a few city site locations. At least on Deity. Maybe GS shakes this up, but right now I find that Builder, Army, Settlers until I can't Settle No More, is usually the ideal build order for my capital to give me the best chance to (a) survive the initial Deity Warrior rush, and (b) get my economy going without capturing AI cities. New cities focus on producing the things needed for tech and civic boosts. I'm seriously doubting that delaying any of this in order to research and build Cothons in the ancient era will be efficient. It may be fun, and a change of pace, but not efficient, and therefore not OP.
What I think Phoenicia is going to be great at is getting more science, culture, faith, and gold from it's extra trade routes, ideally sea trade routes, once you've filled up all your available space with cities and can take the time to build the Government Plaza and all those Cothons (which at half price is quicker than another civ can get trade routes). That should make them an all-round good civ. Not OP, not UP. About right, power wise, I suspect. Time will tell.