Put it this way -- if the byline was really that important, Dragon Precinct would have sold as well as my Trek novels. It didn't. Dave's The Calling should've sold in the same numbers as his Vanguard novels. It didn't.
Neither of those were the same genre, though. In my personal experience, just because I like an author's SF doesn't mean I'm likely to like their fantasy (in fact, I'd say more often than not I don't).
Now, personally I didn't let that stop me from picking up Dragon Precinct
or The Calling
or The Last World War
by Dayton Ward - but I only have/would pick up sequels to one of those three.