Are they even good or should I just read and learn that way in my target language?
That’s up to you, whatever you think that works better for you.
As I have wrote on the other thread with similar subject, you don’t need to learn all LingQs using the Review. You will see them again in future lessons or, when you re-read or listen to the current lessons. Every time you see it or hear it is another review of that word. Most of your review will happen naturally in new lessons. The main thing is to make a lot of LingQs and keep moving. The words that matter will reappear in future lessons.
If you want to do some review using the activities, go ahead. Sometimes it’s nice to mix things up. Or, if you have words that give you trouble, give these a special tag and then filter for those words on the Vocabulary page so you can review those using the activities. In any case, you don’t need to know 100% before moving on. The big thing is not to try and drill every word into your brain. Your brain will learn over time. After a month, if you return to the first lesson you did, you will be surprised at how well you now understand.
Hope this helps! 