This year I got my taxes done a whole day early. Hopefully things will go better than last year. My state refunds took months to arrive and then it turned I had made a mistake on my New York return and had to file an amended New Jersey return.
This year I have already made one mistake. I realized shortly after submitting my federal return electronically that it was missing a form. Fortunately this didn't affect the amount of the refund I am due so I just stuck the missing form in the mail to the IRS but it was still aggravating. I consider this mistake partly TurboTax's fault as it gives you an option to skip things you aren't ready to do yet but then doesn't always remind you in the review phase that you may not be finished. So you should be careful about starting your return before you have everything you need.
I had some of the same issues with TurboTax as in previous years and noticed another problem. In the review phase it summarized my effective federal tax rate for 2013 and previous years but computed it incorrectly for 3 out of 4 years. For 2010 and 2011 it failed to add in the AMT and for 2013 it failed to add in the Obamacare investment income surtax.
I gripe about TurboTax a lot but it really doesn't make much sense to try to do your taxes manually if they are at all complicated. The Obamacare surtax has just added another layer of pointless complexity.