I send my taxes on a paper 1040. The first year they had the free-E-filing I could not get it to work*, so I said 'fuck them' and mail paper every year. The issue I had with e-filing was that I could not do it, because I did not have a printer.
To use the free filing websites, you had to go to the federal one and it didn't give you a 1040-like form, it gave you an idiot question-and-answer format. So you could not capture screenshots of the form as it was being completed.... When I finished with the federal, a window popped up asking if I wanted to print, but it would not allow normal Windows .xps printing and did not allow viewing the print results on-screen, and I had no other virtual printer software. So I could not get any visual copy of the Federal return, and you need a couple numbers off that to do the state return. And you had to proceed directly from the federal free-e-file site to your state's free-e-file site, or else the state filing was not free.... and all the websites let you go all the way through and fill everything out and then tell you at the END that you will have to pay.
So I ended up filling out paper copies of both anyway, and have ever since. Fuck them and their idiot websites. Apparently they are still struggling with the concept of "paperless filing", since now you don't get to waste forms THEY provided, you have to print your OWN forms to waste.
If they just had a way to fill out and email a 1040 PDF, that would be great--but there is apparently no free way to do that.