I started playing Traveller with the "Little Black Books", but picked up "The Traveller Book" when my old LBB's started to fall apart.
Starter Traveller is almost exactly the same contents as The Traveller Book, minus the (admittedly confusing) vector-based space combat system and one or two other minor rule sections. What it DOES have is the seeds for countless hours of fun.
The product is organized into multiple books, but unlike the classic "Little Black Books", the breakdown is functional, not by topic. The first book contains all of the written rules of basic Traveller. The text of this book is extremely close to the wording in The Traveller Book with no inconsistencies that I could find on a cursory side-by-side comparison.
The second book contains all of the tables and charts that the first book refers to, and is my favorite part of this package. This book serves as a GM's screen and play reference, and the layout of the information makes it easy to open the book (or print out a pair of pages) that will cover one particular topic completely. This is a really fantastic way to collect the important parts of the rules for easy access, and I wish more RPGs would do something like this.
The last book contains two adventures, Mission on Mithril (an overland exploration adventure) and Shadows (a dungeon crawl). The version of "Mission on Mithril" is reworked a bit from the one in Double Adventure 2, but seems substantially the same. Shadows appears to be the same version found in The Traveller Book. Both adventures can give a new play group a few evenings of entertainment, and give the GM tools to use in future adventures.
All in all, if you already have one or more Classic Traveller rule sets, Starter Traveller may not give you anything new (except the charts book - that's pretty useful in its own right), but for someone looking to get into Classic Traveller, or who just wants to get a feel for what the original Traveller game was all about, at $6us, you can't beat this package.