If you have a choice, go with the faciltiy that has the CVICU. And magnet status means nothing as fas as actual patient experience goes. Find out the type of patient population that is seen in that facility. Do they do quite a few ballon pumps while the patient is waiting for surgery? Do they place more stents and have in extremely active interventional cardiology department? You want thorough hemo-dynamic monitoring training, and alot of it. You can get it in a regular CCU, but it depends on the cardiologists there and what they will and will not do.
Good luck with your interview.