I'm speaking from the perspective of an 0L, so I can't comment how useful your experience will be in your 1L interviews.
I've been working as a law clerk (doing a lot of "paralegal" work) for the past year, and I can certainly say that this experience help solidify my desire to want to become an attorney. I think more than anything, this experience will help you the most because it will give you insight into the profession and how it runs on a day-to-day basis.
I've learned a lot about the law just through working: learning about how discovery works, "Proof of Service," researching on Lexis-Nexis, and I've even done document review (not fun, just thousands and thousands of pages, and you looking for keywords/ideas). I've learned about how to choose clients, or why we choose the clients we do. I've even had to learn how to bill my time (it's not complicated, but it does take some getting used to).
I don't know what firms will think of the experience, but I can't imagine it'd hurt. It may be seen as a positive since you'll already know how a law office runs, and maybe, you'll be able to get into the swing of things a lot faster.
It's a great experience working at a law firm. i'm sure you'll enjoy it.