I started with a cell phone for business also, but I live in the mountains, which means reception is unreliable. People would call, and my cell phone wouldn't ring, even when it was turned on and I was available, awaiting calls. During conversations, people would have difficulty hearing me sometimes, because the signal would be full of static. Many times they would get a busy signal, even though I paid for voicemail, because the cell towers were too busy to even process the signal to voicemail. Needless to say, it was a professional nightmare!
Is cell phone service stable enough in your area, that it behaves as reliably as a land line?