I am developing application for android and iOS (Mobile)

I know that mobile devices have a difficult time rendering transparent textures (alpha). while running my application in the profiler i noticed that "Render.OpaqueGeometry" was at 50% of Render work and time was at 3.6 ms. i have tweaked the application and got this down to 25% and average 1.8 Time ms. Is this a good value ? or do i need to look at greater optimisation ?

http://postimage.org/image/mg28bcg13/