What do most meduim sized medical practices do? Invest in their own servers or subscribe to Cloud Virtual Servers
I think its going to really depend on your IT staffing situation. I would call us medium sized and we have a pretty well staffed IT department so we are able to keep up on our server upgrades and maintenance ourselves and that is why we host our own environment, but if you have a small IT department I would look at being hosted its pretty low maintenance on your staff. With how many times we have upgraded our software due to new releases, sometimes I wish we were hosted.
Last year, we moved our entire CPS related infrastructure to a Private Cloud. It was the best decision, as I do not have to worry about the hardware or the performance, just the regular maintenance of the software.