wasn't it TurboTax and HRBlock software that was lit up by a class action lawsuit? They, in short, 'hid deductions' from users, and miscalculated others that gave the IRS advantage every time.
I used TurboTax for some filings but not for personal.. for personal I use(d) taxact. I continue to use it as i can import years and years of taxes. The problem, however, is that taxact has gotten as popular as turbotax and have also started to make some deductions more difficult to get to... i can compare former years and see the path to the deduction plainly, and i can reference the IRS to ensure the deduction is still available, but the newer (started three years ago) taxact (just like turbotax and HRBlock before them) have made accessing those deductions more difficult. That, to me, is pure BS.
... and here is the thing: if i had not been using taxact way back when, i'd have never known about those deductions to begin with. they are buried layers and layers deep, but taxact (used to)pre-populate the required information in every place needed... i.e. they would offer you the lower level form instead of making you populate every form in between first- then ask you what it needed to populate the 'missing' (if any) information in the 'in between' forms if it required it.
i was audited back in '09 i think it was... it got hairy enough i secured an advocate to assist. When my day of review came, the advocate reported following "they said your taxes were as complete as any they've ever seen". I got an additional $310 back due to the item in question that spawned the situation (a 1099 my former wife received when she cashed out of an investment, and never told me about so it wasn't included in the filings- it was hers, but we had filed jointly- she purchased the stocks w/post tax dollars and i had to prove to the IRS it didn't fall out of the sky into my lap giving us a $15k return on a $0 investment- once demonstrated she actually lost money on it, they were more forgiving... pain in my arse, though, explaining all that and proving it to them.).... Because my taxes (thanks to taxact) were so complete and well documented, I was pretty much in and out- they didn't have to contact me to question this or question that to wrap it up in one day (after almost a year of waiting for that one day).