It depends on WHICH Epiphones you're talking about.
The '60s models, made in Kalamazoo, were Gibsons with a different look. They used the same pickups, hardware and craftsmen. Give me a batwing Epi over a Gibson any day. Besides, the Embassy gives you extra cool points over a Thunderbird.
In the '70s, when the Japanese took over, they cut costs so much that the Epiphone name was nearly destroyed forever. I think they're still trying to recover from all that damage. If you see an Epi listed as "vintage Epiphone", or has the EA-260 model on it, run away fast.
For the past 20 years, Epiphone has been trying to find their right place, imo. They've had some hits and a few misses. A lot of models were pretty much student models, and not much to brag about. They even tried to revive the batwing headstock for a while. The EBM was actually a pretty decent bass, and they can still be had fairly cheap.
The newer Epiphone seems to have found its place as the place for Gibson to reissue old classics, and branch out to more affordable models of the Gibson equivalents. I wasn't overly impressed with the EB-0 or EB-3, but people talk pretty highly of them. Both the violin basses - the Viola and the EB-1 -were nicely done. I've had a couple of the EB-1 models, and have liked them a lot.
The Jack Casady and the Allen Woody Rumblekat are Epiphone exclusives, and both get a lot of praise. Casady is really involved with his sig bass, so he pays attention to what they're doing with it. I guess the model has been modified over the past few years, based on his feedback.
The new Embassy? It's not a real Embassy. I'll pass.
Then, there's this one (technically called the ET-285):