I used TurboTax for years, but last year went the Free Fillable Forms route. My process was:
- Do the forms by hand, to get a number
- Do TurboTax (free to start!) to verify that number
- Enter the info from my paper forms into Free Fillable Forms
- Print off state forms and mail them in
More complicated than it needed to be, but I liked double checking my work.
However, this year, having upped retirement contributions, I actually did qualify for the Free File software, but I only found out about it after steps 1 and 2 above. Since Turbotax wasn't one of the options, I figured it was probably going to be less work to just do the Free Fillable Forms at that point.
Only I forgot that you have to key in your entire W-2. And that State was not part of the Free Fillable Forms but would be part of the Free File software (for my state, at least).
So, I didn't save myself any time and also paid for two stamps (I opted for a 9"x12" envelope for state) that I wouldn't have had to do if I had just done the Free File. And then my federal return was rejected twice because I miskeyed the W-2 and I missed the box where you total your exemptions (assuming, wrongly, that the "calculate" button would do it for me).
Overall, I would recommend Free Fillable Forms; it was easier for me than TurboTax, and I'm planning to try and convince my sister to do her more complicated taxes that way. But I would not recommend using Free Fillable Forms if you qualify for IRS Free File.