Yeah, it's easier showing and telling, but it's IMMENSELY more difficult to plot a book where the character can't see around the corner. You have to use a variety of techniques to get the right information to the MC (main character) to "guide" them to find out things. Lots of people do a great job with internal stuff, but then fall down when it comes time to advance the actual plot. And in a subgenre romance, it's even trickier because you're doing a DOUBLE arc plot (paranormal mystery as one, romance as the other, for example.)
I really enjoy writing first person, but also really enjoyed doing the third person books we're putting out right now. A lot depends on the story. I think paranormals are easier to do in first person because there are more methods (such as magic, or psychic ability or mental conversations) with third parties that can advance the plot while the MC is doing something else.
JMHO, of course.
As for your other question, aspiring---Harlequin has FAR more readers. Cerridwen is a fairly new imprint of Ellora's Cave, and there are more readers of traditional paperbacks than ebooks presently. You won't find any of Cerridwen's books in Waldenbooks, or WalMart. That's a pretty big market for romance readers. You also won't see an advance from Cerridwen (meaning money in your pocket before the sales are tallied.) Harlequin DOES pay an advance.
But things, they are a'changin. Cerridwen might do well enough in sales to wind up on the bookstore shelves, like many of EC's other books have. Only time will tell.