Even using a GUI for it? There are several which should make it easier.

I never really had problems with the CLI version though.

Edit: I suppose an alternative would be to use something like Tranzcode to extract mono wave files and then use your favorite audio encoder to convert to DD from there.

I don't know how much development it's been under since eac3to is everyone's go-to program, but it looks to be a bit easier to use.

Edit 2: What is important is that eac3to can be set up with the DTS decoder of your choice. Sonic's decoder is reference (and some say Nero's might be as well). That would give eac3to the edge on accuracy over other methods.

Edit (cough) 3: I would be remiss if I didn't also suggest NicAudio. It let's you decode via avisynth. http://nicaudio.codeplex.com/