I have used TurboTax for 20+ years, and I like the methodology of filing taxes. However and after exhausting all sources I knew of or were available, I was not able to efile the return and I have to mail it.
Turbotax does a great job and helps the process of surching through problems.I really appreciate their methodology and helpfulness and will use it every year.
Overall, very clear and simple to use. Download from brokers saves time. You might make printing of Estimated Tax Vouchers optional, since the IRS does send these to many taxpayers, or arrange to print them on fewer sheets.
What's great about it: Clear instructions, with timely reassurance that the program "will get back to that."
What's not so great: Very few. You might explain the "Back" function uses "X" at top right.