I use QuickBooks 2003 myself and personally don't like 2005. It takes forever to load for one, and there aren't really any nifty features that I need, or features that I'd use which aren't in 2003.

If you have employees, unless you outsource your payroll, calculating it is a pain with QuickBooks. You're on your own when it comes to calculating percentages, and then if the company also contributes (Medi, Soc. Sec. Tax) you need to make sure you put the same amount on the company side. Otherwise it will be a headache to go back later to fix this when filing tax forms. Depending on the number of employees, it could be beneficial to pay for QB to manage it. But for one or two -- it's not worth the cost.

In regards to its limits for transactions, it depends what type of volume you have as well. Most people won't reach the limit in a year, I never have but thats because of the business I'm in.