The Pentax LX was the professional 35mm system offering of the brand, which featured swappable focus screens and view finder housings. Along with many other options the LX system can be customized for personal preference. The camera is smaller and lighter than its competitors and offers weather sealing which was very uncommon at the time. Most LX's come in black, unless a special edition presents itself in silver. The black paint has a black coating underneath to help keep the stealthy look even as it receives wear.
The LX offers an aperture priority auto mode on the speed selector dial, unique in that most cameras of the time only offered shutter priority auto modes. The ability to shoot double exposures in camera, similar to the Canon EF, is an appreciated feature. The only thing this camera lacks is an AE Lock button, which can be solved by metering and then utilizing manual exposure. The Pentax LX is a wonderful camera to use and it produces excellent results with the SMC lenses. So far I like the color reproduction and saturation levels from this system the best, as compared to my other cameras while shooting Kodak Ultramax 400.
Here is a nice review with more information about this camera: Casual Photophile-Pentax Lx