I have been using their tax software since 1993. It is very easy to use. All you have to do is click on only those questions upon which you have received 1099s, W-2s, Social Security, etc. Very easy to understand. Have never had a problem.
I buy the deluxe software that includes the state tax forms. This year the state form downloaded easily and I love how the data is carried over from the federal form to the state form. It makes it so easy to finish the state form.
I have used H&R Block tax prep software for around 10 years. I have found that it works flawlessly and prompts me to input the data so that I can maximize my IRS and state refunds.