with true all in one boards all you need is the board, a power supply and connect it to your PC and stepper motors. The limitations of an all in one board are:
1/ if something goes phut you're doomed to replace the board unless you have the skills (or know someone who does) to diagnose and remedy
2/ they are usually a compromise as compared to individual stepper drivers - typically lower output (esp when all axis are being used), lower max supply voltage; With individual drivers you can match them to the steppers to get better tuning per axis
3/ the kits with steppers included are often poorly thought through, with bad (read cheap) choices of motors for the board;

Having said that, they can be good value for money if you aren't impacted by the limitations (i.e. most small starter machines) and aren't dependent on the board (i.e. hobby rather than any thing else)

Personally, I'd look at something like DIYCNC's System4 if you want an all in one solution without the limitations... not that much more in price and UK support plus it is well liked...