It was something about time travel and the rewiring of history so that Brythaic (Old Welsh) became a prominent language and the Arthurian Court had survived to modern times, except the author was very selective about which bits of history changed. Can't remember the title, but just remember how poor I thought it was, though it had been traditionally published.
In my teenager years, I devoured the "Gor" series by John Norman. Obviously, I was not reading them for character development or really varied action. Looking back, they were dreadful.
Later, I invested a lot of time in the Piers Anthony Incarnations series that I felt was a great step down from his Split Infinity series. I know each book was supposed to have a different feel to it but I just did not get it.
Recently, I was greatly disappointed by Orson Scott Card's Mither Mage trilogy. Incredible premise, strong first act of the series but then a second act that just drug without much of interest and a finale that dug up one of the worst Deus Ex Machina I have read in perhaps forever (nod to Stephen that I have not read the "of thorns" series. And now I don't want to.)
And i would be remiss if I did not add books 7-10 of the Wheel of Time series. Overall, it is one of my fav series of all time but Robert Jordan just lost his way as he got sick. I really, really, really did not want to read 14 chapters about only one of the 1,900 major story lines he introduced in the series (slight exaggeration but not by much).