Been considering hiring a professional because you always hear that they are worth their weight in gold. (Our tax situation is not particularly complicated though, typical Silicon Valley married homeowners).
Well, last year, did everything in turbotax, said we were short by like 15k. Believable, BTDT before, but didn't want to believe it. Hired an accountant on a recommendation. She did all our stuff, came up with a bill, turned out we owned $500 more than TurboTax said.
Okay, paid it.
2 months later, get a check from the IRS, we overpaid by $500. Yup, TurboTax had it right all along!