This is not as bad as some of Ehrman's later works, for two reasons.
One is that he has more items of actual value here.
Two is that his popularizing schtick, from the titles of his books on, through the thinness of his popularizing info, wasn't wearing thin 15 years ago.
The best good part is noting that the pseudo-Clementines' battle between Peter and "Simon Magus" is really a battle between Peter and Paul. Ehrman somewhat ties the actual origin of the books of 1 Peter and James to this, though he doesn't go as far as he could, and more critical critical scholars do, to emphasize how much these books are designed to make Peter and James sound like they're supporting Paul.
Second is debunking not just Da Vinci Code cult surrounding Mary Magdalene, but many Xns, from medieval popes through modern evangelical teachers, conflating her with other Marys. I will give him an extra kudo for mentioning the Phibionites; in my reading about Epiphanius, I'd not come across this particular "heresy."
Overall, the book is fairly good on this, and related issues such as women as witnesses to the empty tomb. It's decent but not great, other than the pseudo-Clementines, on Peter and Paul, with some failings there.
And, that said, what's wrong with the book?
Like other Erhman books, this has one problem that is common to them. He dates all four gospels too early. Mark, IMO, is post-70. Matthew is almost certainly post-85 and Luke post-90 if not post-95. Acts is likely at 100 John, even in semifinal and not fully final form? Post-100. I know I'm out of the academic norm on Mark, but I can justify it. I'm not out of the academic norm, at least not way out, on the others.
Second, he ignores Pauline factors in the denigration of Peter.
Third, as for the alleged early success of Christianty, Ehrman starts a mental thread that plays on his writing 15 years later. Christians did miracles. They reflect pagan stories of the gods (like Zeus and Hermes visiting Baucis and Philemon. (A deconstructionist critic would aay, hey, Ovid put this in Tyana, where Apollonius was from, and Paul wrote a letter to a Philemon, and would go from there.) Pagan miracles of the present, like the aforesaid Apollonius, don’t get mentioned. Nor do Jewish miracles.
Fourth, as he (and I) deplore mythicists "arguments from silence" on some issues, he does the same on Jesus' alleged celibacy, even when the answer from 1 Corinthians is staring him in the face.
Paul says celibacy is to be preferred, but not everybody has "the gift" that he does.
Well, Paul can't be above Jesus, and all three Synoptics are dependent on Paul, somewhat directly via Markan material and somewhat in a broader sense. (Ehrman also tries to put too much daylight between Luke and Paul on interpretations of Jesus' death.)
So, Mark doesn't talk about Jesus having a wife. (If he was writing from Rome, and had seen Paul's letter, that might have been an influence.) So Matthew and Luke don't, either. (The "sayings gospel," known academically as "Q," presenting Jesus as a Jewish counterpart to an itinerant Cynic philosopher or similar, would have taken him as celibate for those reasons.) John may have heard enough, at least orally, from all three synoptics, and other sources, to just go forward with this. Anyway, just because no gospels list Jesus as married doesn't mean it's true.