This is a review of the Discovery Kids "Motorized Train Set" I'll use a mix of stock pictures and my own pictures for the review. You can see a video of one in motion and compared to it's PlaRail counterpart here:
http://www.blueplastictracks.com/showthread.php?tid=130

I purchased this this set for $30 at Kohls Department store in a suburb of Chicago. The price was approximately 50% off the original price.

Overview:
The box shots show pretty well what is in this set. It's a fair amount of stuff.

The Train
All the connections on the train are the Plarail style loops (no hooks) with half of them turned sideways. It is functional, but not as nice looking.
The engine...

...and coach...

... are pretty clear Plarail knock offs. The switch is different, but the rest of the mold/cast seems to be the same. The paint job is pretty well done and the train feels sturdy. Unfortunately the sound is louder and a bit more grating than Plarail/Tomy Engines.

I think the Caboose may be an original design is has a "DK" emblem on the top and unfortunately the raised roof and stairs sticking out from the side take it outside the metrics of most Plarail. I have a feeling that it will catch on the side of some stations.

Scenic elements
The Station, sign and Tunnel are nice pieces. I especially like the art deco look of the tunnel, even if it is a bit bland.

Tracks and Trestles

The Trestles are clones of Plarail designs, but are ever so slightly (perhaps one mm) larger. Thus, they will fit on top of Plarail elements nice and snug, but putting Plarail tresles on top of them does seem to stress the Plarail elements a bit.
The silvery grey Tracks are all clear clones of various Plarail elements with slightly different details and connectors. The quality and types of plastic seem to be comprable with the types of plastic used on Plarail tracks.

As seen in my pic above, the Male end of the DK tracks will fit nicely with the female end of Plarail tracks. However the reverse does not work. If one likes the color, it would definitely be worthwhile to cut a few pieces of the track to accept the male end of a Plarail track connection, but I haven't bothered yet.

It is a bit annoying that it only comes with one ramp piece and the other slope is just regular tracks on stepped trestles.

Summary and Conclusions:
This set is not worth the $60 price-tag, but at half off, it represents a good opportunity to pick up an uncommon style of train and some useful (and in some cases unique) scenic elements. I acquired the train a few months ago, but there is still a chance that there are some of these sitting at some of the many Kohls stores across America.

For my use:
I definitely plan to use the train, trestles and scenic elements. I might do a bit of modification to make the caboose stairs stick out less, as I really do like the way the whole train looks chugging around my track even with the roof emblem. The track, I'm not sure about. I may use it for a loop of it's own at some point, though I haven't run out of BlueTrack so haven't needed it yet .