Any GTers with decent finance know-how?

I was planning to max out a traditional IRA before 4/18 to maximize my tax savings, which would give me a hefty tax return. I signed up with Betterment, after doing a bit of research about the best robo-services, and after I entered in all my information, it recommended I max out a Roth IRA instead, which has no upfront tax benefits.

I think they made the recommendation based on my saying I expected to be in the same tax bracket at retirement. But I have no fucking idea what tax bracket I’m actually going to be in at retirement, so I’m not sure how sound the advice is.

Since I’m not sure, should I do half and half? Or I’m planning to max out an IRA in the 2017 tax year as well — should I maybe do a traditional one this year for the tax benefits, and a Roth next year?

I am so lost about all this stuff. Investing hurts my head! Any help/thoughts/suggestions would be greatly appreciated.