Turbotax is fine, the alternative to them would usually be Ufile in my opinion. My answer would vary depending on what functions you use in TurboTax and if the bells and whistle are necessary in your opinion.
I am not a fan of online tax returns... So, my only complaint for SimpleTax would be that the return is done online, not sure I trust most online tax returns since the data could be stolen due to your browser been compromised or (maybe) the provider. I would stick with a software that is run on your computer IF you can since it allows you to store (I store my data on a USB stick, not on my computer) and manage your data. I also don't want to minimize any trace of data from my tax return on my day-to-day computer. This way, the programmer has no access to your information (since you are the one uploading the data to CRA server) and your browser won't have a chance to store some of the data in the background without you knowing (auto-fill anyone?).
I used StudioTax in the pass since it was free, but they want to charge for the first time this year. I personally had some issues while entering my RRSP last year and I don't find their wizard very polished so I am not willing to give them money for the software.
I plan to use Genutax this year since it's still free. Mind you, I am doing 1 return and I have an accounting background, so I am not too concern about the wizard (I check the work thru the worksheets).