I haven’t used either one, but either one can work, because the most important factor is you bringing your determination to learn the language.
I taught with about three methods for teaching English when I was in Santo Domingo; one was a textbook in a normal classroom setting but for typical private school kids (I didn’t last long there). Another was “Ms. Clarice’s English School”, which was similar.
But by far the best was a Dominican guy who had family ties in Holland but spoke perfect American English. He had researched the best way to teach.
Optimum class size 6. A few dozen stick figures for some common nouns and pronouns, with the word below the figures. Memorize and review. Then a few dozen action verbs in the present tense with stick figures to illustrate and the words below. Then verbs in other tenses, and on from there. Didn’t last long because I think he expected faster returns.
Mr. Berlitz himself said he didn’t study a language more than 15 minutes at a sitting, come back later.
I read Barry Farber’s book, “How to Learn Any Language”, for me fascinating. He goes over the various methods and analyzes them. Then he says pick the one you like the best because any of them will work if you are motivated. He’s fluent in several dozen languages. Other people go to the beach for the weekend, or opera, he’s told people he’s going to learn another language this week. Love the book. Hardest language to learn: Finnish. Easiest: Indonesian.
Here’s a short “clip with quips” from one talk he gave on the subject:
As an aside, he was helping Hungarian refugees escape after the Freedom FIghters that pushed out the Russians in 1954 were stomped on by the heavy Stalinist boot.