They ought to be fine. 2.79 still gets changes frequently (2.79 MacOS just got OpenMP support for accelerated simulations a couple hours ago) so there’s always a chance that there might be an issue with a particular daily build, but in general it should be much improved over 2.79b.
The 2.79 experimental builds get you two things: 10 months of bug fixes and minor enhancements beyond what 2.79b has (with exactly the same hardware requirements as 2.79b), and the newest version of Cycles that’s identical to the version in 2.80.
The new version of Cycles has the latest enhancements like the Principled Hair shader, GPU+CPU rendering etc., but it also comes with the new hardware requirements for minimum CUDA compute capability etc. and no longer supports AMD GPUs on MacOS for Cycles GPU rendering. On the plus side it does include support for the latest 20x0 Nvidia cards.