Your mileage of course may very, so as with any advice and Internet forum please take this with a large grain of salt:
I’m pretty particular and precise with presentation/fonts/spelling/etc., had taught resume/interview courses in a different industry before making the career switch, and had already attended one of their ALPA workshops and spent the time to incorporate those suggestions into my application prior to buying their services.
I can say that they provided a tremendous value to me at the application, resume, and interview stages. I was skeptical at first but it is some of the best money I’ve ever spent.
Two caveats:
(1) I didn’t come from a large 141 school/university or military and had a varied career (both aviation and non-aviation) prior to entering 121.
(2) I did both interview prep sessions in person in Denver. I knew ahead of time that I do much better face-to-face and worked out my schedule accordingly to avoid the phone prep. I did the application review over the phone and it was excellent and comprehensive.