For me it was harder to go from 5-10 cm. The first 4cm can still be classed as early labour as the contractions tend not to be as strong and are generally further apart too. The second half of dilation can be a bit harder as they are stronger and closer together. That said it can vary so much from woman to woman too. A syncto induction can be a lot harder in terms of the strength and duration of the contractions too, but if you don't have an induction this time you will notice the difference between them - I felt a lot more in control with them as even towards the end of the first stage they can still have a rise and peak in their strength kwim? but an induced one was just bang, bang, bang.