The design does not lend itself to lone tablet use, which makes Microsoft's website marketing of the device as a solo tablet a little confusing. Clearly the draw of being able say the Surface 3 sells From 419' was too strong to resist.
However, the 529 bundle actually offers far better value. It includes a Type Cover keyboard, plus effectively free' upgrades from 64GB storage to 128GB and from 2GB to 4GB RAM. Any buyers picking the entry-level 419 version have made the wrong choice.
Hardware
Both have the same external features, though. The frame is metal, and a kickstand holds the screen at three different positions. It gives a laptop-like setup with the keyboard attached, or something closer to the world's smartest picture frame without.
The combination of multi-angle hinge and removable magnetised keyboard base still offers a form of flexibility not offered elsewhere, though. Not even in most other hybrids tablet-laptops.
The more expensive Surface Pro 3 has the edge here, though, with a stand designed to hold the screen at almost any angle. It uses a more advanced, stronger hinge, one that would presumably be too expensive or difficult to incorporate in a tablet this size and weight.