Quick Books is inexpensive and more then adequate for use by Start-Ups. I know of many companies that have used Quick Books from start-up through revenues exceeding $25 mill. A SV story goes that Seagate used Quick Books with revenues up to $100 mill.
I would recommend not spending a lot of money on accounting systems in the early days of the company. It is a waste of money. I have been running a 75 person international company with multiple locations on QuickBooks for a number of years, just fine. QuickBooks Enterprise may be more than enough for most companies for a while. Your accountant can take care of revenue recognition activities. For subscription ( SaaS ) related activities, I would splurge a little on solutions like Zuora a little later. This will help you with more than accounting. It will help you with churn management.
@David Johnson would you recommend NetSuite for a SAAS business? Also, NetSuite is quite expensive (I have been quoted 50k a year + 50k in prof services), is there a threshold that you recommend people cross before considering it?
The longer you wait to transition from QuickBooks the more costly it will be. If you have revenue and are growing, now is a good time to transition to a more robust accounting software. It will payoff in the long run.