It really isn't horrid in the sense of Gothic at all, but some might find it horrid in the sense of amazingly pedantic and hard to read. I actually enjoyed it, but I have questionable taste. ;-)

As Elena said, it's full of incident and features a main character who is meant to be a pattern of male perfection. Richardson wrote it in part to counteract the appeal of Lovelace (from Clarissa) who was much admired by some for all the wrong reasons.