I haven't read the series your talking about, but for years LOTR has been the benchmark for Fantasy. It's simple, LOTR came first, at least as far as a trilogy goes (I know, there's a great tradition of Fantasy novels, but prior to LOTR they were never main-stream). It's always going to be the standard against which new writing will be compared in the Fantasy genre. Even Tolkein didn't always live up to his own standard; the Silmarillion was one of the hardest Fantasy novels I've ever waded through.
As to the series your reading, if the author has a good writing style, and the books remain interesting, who cares how long the series goes on?