We have most of the Trolls sets because my kids (unlike the person who gave the set a 1 star review) love trolls and were super happy to see these sets come out. They do seem to have less pieces them most similarly priced sets but that makes them great for younger kids. My 4 year old, with the help of her sister (7), was able to build most of the Trolls sets with minor frustration. If you have a little one who likes Trolls and is ready to start building on their own, I think any of the trolls sets are a good fit. Also, Biggie and Mister Dinkle are so cute!
My daughter (6yo) got a few of the Troll sets for her birthday and she LOVES them! She is an advanced builder for her age, but wouldn’t be difficult for any other 6 year old! She wants to collect all the characters now... she loves having movie themed Legos to continue to play with after building :)