Brought this set as the authentic Thomas expansion sets are ridiculously priced.
The selection of pieces is good and offers a whole lot more options than I had before. However I am slightly disappointed that the quality of the wood is nowhere near as good as the authentic 'learning curve' pieces we already own. The original pieces just got together very well and feel like they would look as good as new even after years of use. By contrast this set is made of the very cheapest pine, and consequently one or two of pieces had corners split off upon getting it out the box. This hasn't affected its functionality, although they are also a slightly loose fit. Also the very basic style and paler colour does also make for a patchwork effect when combined with a original beech set.
You get what you pay for and I guess, and arguably my complaints are only minor. This set clearly does represent good value. However I do also find myself rummaging through the whole set to find a 'learning curve' piece wherever possible. Which does make me wish the whole set was all the same.
I guess if you can stomach the cost of the authentic set, then do so. If not this is a great value alternative.
(I should point out mind you that my two year old son hasn't yet complained)!