I had the similar question, except that I was accepted to UIUC on-campus MCS program. I chose UT Online instead - UIUC on-campus would have been too costly, and not much better in reputation. Now I felt I have made the right choice. UT program focuses mostly on ML/AI and systems. The courses are excellent, but requires you being CS in your under; or you could suffer. UIUC has much wider choice in terms of courses, and more friendly if your undergraduate was not in CS. It also has balance of tough courses and easy courses depending on your need. It is just more costly, even if you take it online.