Hi,
I would suggest going for the 4.0 exams. I would do this for 2 reasons
a) You are not running behind (once you got the 3.5 exams done you have to upgrade sooner or later ... and who knows when the next version comes out? If a new version comes every 2 years, then we can expect the enxt release in little over one year ...)
b) One certification less (the 70-536).
But of course: Everyone has to decide himself. One reason against it can be, that some self paced training kits are still missing ...
With kind regards,
Konrad