We don’t speak Spanish, and my son used Tell Me More. He got the homeschool version which is two years of high school. He did one year of it, but retained very little. Foreign language and vocabulary are his weak points. His sister used it also and had conversations with him, but not enough for fluency. It is very difficult to keep a foreign language usable if you are not using it often.
The following year, we did sign language as a family. My daughter loved it and was a natural. She uses it daily and is going to become an ASL teacher. Thankfully our church has a deaf ministry, so she can use the language often.
All that to say, I think whichever language a student has the best access to use often is key.
We use library videos for practice too.
Tell Me More is fine if the goal is to earn high school credit. If you want fluency, lots of time with native speakers is needed.