Just get them trying to answer the following couple of questions…
“So where exactly is my data hosted? In whose hands is it? And who is looking after it? What if there is a breach? Is there a possibility of someone mis-using my data? Who is in charge? What if my competitors get their hands on it? What about patient confidentiality? How do I get my data back, should I decide to leave?
My rooms are open till late at night; what happens if I cannot access my patient files after your closing hours? What happens at my practice if I lose Internet connection with my ISP?”
Did you get unsatisfactory answers from a snake-oil salesman? Then be pragmatic and stick with what you have.