tough question, without knowing how many you plan to file, cost, etc.
and if you have a TCC number that might make a difference as well. I think most softwares you don't have to have one, but some may give you the option of filing under theirs or yours, with a difference in price.
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We use FT William (with their 5500 software) but I don't think that makes a difference if you don't use the 5500 feature.
I find it real easy to use, one nice feature is by typing in the company EIN the software pulls the basic information on the plan and populates much of the info on the first page. If you have lots of SSA for a particular plan they have a fairly easy to use excel import file as well. but then I'm speaking having used the system for a number of years.