I have had the privilege of running on both tracks multiple times.
Both are great indoor tracks. DePauw has a great wide open feel to it and lots of space to warm up and move in it. Plus they have an amazing trail system right outside the door if you would like to go for a longer warm up or cool outside. It was nice to have the option of indoor or outdoor warm ups.
At Purdue I liked the intimacy that the smaller area brought, but I did think the turns were a bit tighter than DePauws track. A few times the Purdue athletes were able to take a few seconds off of their times run at their track for conference because of how tight the track was. (Like the opposite of adding time because of an oversized track...)It was interesting getting used to having the stands above you while you were running. I had to warm up outside on the streets there because of the lack of space inside the track.
I really did enjoy both tracks, so I don't think you can go wrong. But I do have a personal bias towards depauw :) I think it depends on what kind of atmosphere you want and what kind of warm ups your kids are willing to do.
I ran at the boilermaker invitational at purdue for two years and all of the track meets at DePauw. Loved racing in both!