Traditional 401k VS Roth 401k

My company has both traditional and Roth options in the 401k, i currently do 7% traditional and 3% Roth.

Do you think this is a good option?

I know traditional is pre tax so I pay less taxes now with the hope to be in a lower tax bracket after 65. The Roth gains will be tax free in the future which is amazing .

Main question is will the traditional hope for lower tax bracket outweigh the the tax free gains the Roth can offer?