My twin 5-year olds have had this toy since last Christmas. They love it. We have (I think) a prior version with less memory-we're only able to store about five books on the pen (as opposed to 10, as the review indicates).
The TAG was very helpful for my girls as they began to read stories and recognize words by sight. Leapfrog has an extensive library of books, so there's lots of variety to choose from, with characters the kids recognize (Dora, Diego, Spongebob, etc), as well as kid's classics like "Cat In The Hat" and "Chicka Chicka Boom Boom". We purchased the carrying cases as well, which provides handy storage for several books and the TAG pen. We take the TAG books and pens on long car rides - keeps the kids busy for a good long while.
I also appreciate that there are many "levels" of exploration with this toy. The child can use the pen alone, and listen to all of the audio for all stories downloaded to the pen just by pressing a button. The TAG will cycle through all of the stories. The books themselves are also multi-dimensional: You can just read the story, or you can play the games embedded in the books and earn rewards on the Leap Path website. My girls also like to explore the books, and place the pen on the pictures of the characters themselves - Leapfrog has embedded some cute dialog as well. For instance, when reading the Spongebob book, if you place your pen on Spongebob's face, he'll say something funny related to the story.
The LeapPath website allows parents to drill down into each book the child has read, total minutes the child spent exploring the story, and cool info on what skills the child is building.
CONS: The TAG EATS batteries. Be sure to have a supply of AAA batteries on hand. The volume could use a boost; my daughters are sometimes holding the pen to their ears in order to hear the narrative (they're not too fond of earphones, so that's not an option for us). Downloading new stories to the TAG pen can take a little while; its not a horrific wait, but it can seem like forever with an impatient child jumping up and down in front of you, waiting to read a story and use his pen.
All in all though, an awesome toy.Get more detail about
LeapFrog Tag Reading System (32 MB).