There's another thread called "Accelerated Audiology" that has some more insight on their program. I was also offered a 90% tuition remission (out of state) plus an ASL assistantship worth $11,000. It was hard to turn down, but I did it because of the reasons you stated. For me personally, I don't think I would be confident enough in my skills after just 2 years, to start a full time externship. Yeah, I'm a little older and loved the idea of being done at 31 instead of 32, but I think the extra year spent working with preceptors, mentors, with supervision and guidance will make me a better practitioner. I've historically struggled with self-confidence in work settings so this is very much just a personal preference.
Also, I want to be a pediatric audiologist, and the opportunities at IU just didn't seem as strong as other programs I was accepted to.
The "Accelerated Audiology" thread has comments from a current student; I would DM him/her for more insight! Good luck in your decision!