I got Jordan's Conan the Magnificent when it first came out in paperback along with Poul Anderson's Conan the Rebel. Funny thing is that, in reading the GM book of the Shadizar boxed set, and realizing that much of it contains information from Conan the Magnificent and decided to read it again, the first time I've done so since 1984.
I'm really not impressed with the story, and wouldn't recommend it as a Conan story. It reminds me why I don't tend to like pastiche writers. Before the angry responses come, let me say that I also read the first book of the Wheel of Time series and was infuriated with the poor, protracted writing (his usage of "Just" just appearing just like just 16 times per page, at least that's just how it just felt). BUT, I think Magnificent is a much better written story, it's just not a CONAN story. Conan acts fine if he were Sinbad, or maybe one of the English soldiers in Gunga Din. But he's way too civilized to be a barbarian newly arrived in Zamora; and while I like Jordan's writing that Conan cannot ever understand women, his actions are too civilised and gentlemanly to feel correct to me.
The women in this story are pretty well written, in a stereotypical way. Their actions are predictable in a "Perils of Pauline" sort of way, but isn't that expected as a convention of the genre? As for Eldran the Brythunian, I get the impression that he was the character Jordan was most interested in writing, and used the story as a way to deal with a character he was much more interested in. There are just too many elements in this story that feel out of place compared to Howard or even de Camp/Carter/Nyberg stories (the hillmen, the monster, it's inability to be harmed by weapons save the bane weapon -- I KNOW THE FLAME KNIFE also has a bane weapon, but Jordan just doesn't really explain any cosmic works affecting the beast, it's just untouchable because it is). Conan's sense of humor, his foreplay, even his reactions to taunts or bribes or such would work well in something like Sinbad or Tales of the Arabian Nights, but just don't feel like, well, like Conan.
I DO however like most of the way Shadizar is depicted, it's flavor, most of the atmosphere its well-laid. Interestingly the king is practically unmentioned, neither are it's religions, but the nobility depicted through the Lady Jondra are, well, interesting.
There's me two cents woith. In conclusion, it's interesting to read Conan the Magnificent if you have the Shadizar boxed set and want to read where much of the source material comes from, but I don't count it as a great Conan story. It IS a good adventure/fantasy story, if you substitute another person of the Hyborian world for Conan.
End of line.