As far as career prospects, I do think attending Interface helped me get the internship that lead to my current role as a software engineer. I will say that after attending Interface I started attending courses at the local community college with the hopes of getting an Associate's Degree, and that probably helped in getting the internship (I eventually abandoned that in favor of a Bachelor's Degree in Web Development). However, I was not far enough in those community college courses to have gotten the internship on those.
I do know some people that have gotten jobs after just attending Interface. And of course some people have not gotten jobs after attending. What I think really gets you a position somewhere, and what played the biggest factor with me getting the internship, is working on your own projects and education. In other words, you must show initiative and desire. I didn't have much in the way of completed projects but I had been working on several, and the interviewers could tell because I could talk about the details of them. So I think Interface will help you get a job, but you have to go the extra step and actually use what you've learned. Make a mock website or work on an app on your own. Even a college degree won't help if you don't show a real drive and desire to an employer.
As far as the cost, can you do courses online that are cheaper? Sure. But the advantage of a school like Interface is actually having an in-person instructor with whom you can ask questions. Yes there are boards online for getting answers, but there's nothing like having someone that can actually look over your shoulder at your monitor to see what exactly is going on. Plus you don't have to wait for a response to a question.
Another thing I liked about Interface was the schedule. There is another code school in Omaha that is very good, but its schedule was all day every day, whereas Interface met in the evening two times a week. This allowed me and others to keep working while we attended, which was very important since I have a family to support.
So overall I highly recommend Interface as a way to jump-start a career in web development. But remember - anyone can take a course, but it's what you do with your education afterwards that really matters.