The biggest downside I see for getting outside IT help is that you are dependent on someone else. The doctor next door to me has not been able to see patients since yesterday afternoon because their server crashed and the IT guy who does their service cannot come in until until today afternoon - about 28 hours after the crash of server. So they have been unable to see the patients. The office is closed!
Lesson learnt is the computer configuration in the office should be simple enough that you can fix most problems yourself without the professional IT help. Fortunately, AC Main Computer on a good Windows 7 (i7 with 8 Gb) on a peer to peer network functions well - as good as Windows 2008 or SBS2011 server.
My advice is to keep it as simple as possible that you can fix most problems yourself and are not reliant on outside vendors.
