Something to think about when you're about to use microvias:
- Increased available space, shorter signal paths, better HF-characteristics.
- Components with high pin density and many pins drives the choice of technology.
- Higher packing desity and finer tolerances affects the yield in production.
- Check the standards for HDI (High Density Interconnect) and if the manufacturer can handle theese.
Let your designers do what they do best, and I will take care of the PCB Design.