The Blackberry Curve is the cheapest Blackberry currently sold and in my opinion this shows in the quality of the phone.
A positive of the phone is that it has all the basics you expect from a Blackberry, such as Blackberry Messenger and Blackberry App World, however comparing these applications on the Curve to the same application on a Blackberry Bold they are very slow running and inconsistant.
I used to own a Curve and now owning a Bold I have no idea how I lasted two years with the cheaper and poorer quality model. In the two years that I owned the Blackberry Curve it was sent back four times each for a different reason (broken keys, screen would only show white, clock showing constantly in the middle of the screen and the phone turning on and off on its own) and yet I have owned the Bold now for a year and not had one problem.
I would thoroughly advise anyone who is considering getting a Blackberry to go for the Bold, it is the best quality Blackberry on the market and the Curve is by far the worst.