2 years separation is the only option for a no-fault divorce at the moment. After the 2 years is up, the Respondent still has to provide consent when signing the acknowledgement of service.
If they do not consent, the only option is to wait another 3 years (5 years separation) or divorce on the basis of unreasonable behavior.
If you want a divorce asap, I would suggest divorce through the unreasonable behavior route, nobody else outside the case will see the reasons and they are seldom contested. If you wait 2 years, there is a risk the other side will not provide consent then you are back where you started!