anyone use the miniature OEM GPS modules with built in antenna?

[Mook Johnson]

I'm looking into using one of these $50 GPS recievers and was wondering if
anyone had used them in a design.
I'd like you what your experiences were with this unit (or a similar ones).
My intended use in an open field and will be mostly for speed measurements.

thanks.

http://www.deluoelectronics.com/customer/product.php?productid=89&cat=19&page=1

http://www.deluoelectronics.com/customer/product.php?productid=180&cat=19&page=1

http://www.mightygps.com/oem/12channelgps.htm