http://www.dpreview.com/news/2011/6/3/pentaxgps2. ASTROTRACER for effortless astronomical photography
When mounted on the PENTAX K-5 or K-r camera body, the O-GPS1 also offers the advanced ASTROTRACER function,** which couples the unit with the camera’s SR (Shake Reduction) system and enables users to photograph celestial bodies. The unit can calculate the movement of stars, planets, and other bodies using the latitude obtained from GPS data and the camera’s alignment data (horizontal and vertical inclinations and aspect) obtained from its magnetic and acceleration sensors, then shifts the camera’s image sensor in synchronization with the movement of the objects.*** As a result, stars and other bodies are captured as solid points rather than blurry streaks, even during extended exposures.
Sample of some images in this thread taken with the o-gps1, the Op's shots are all single frame non stacked up to 160 seconds
At the end of the day choose your camera for what you want to do with it , i chose the Pentax for its price, ease of backward compatibility with older lenses from previous Pentax cameras i have owned, low noise , low light capability and added gps ability.
Believe me when i tell you that although it is a wonderful camera DO NOT expect to find many shops in S.A. who deal with Pentax camera's , lenses or even 3rd party lenses for Pentax.
The majority of shops in S.A. sadly only understand 2 words Nikon or Cannon.
If you are looking at lenses to go with your choice, i would recommend buying a magazine called What Digital Camera , they give a nice breakdown of all lenses for all makes of cameras, as well as listing 3rd party lenses that work on the major brands, such as sigma or tamron for canon, or nikon or pentax etc. Some of the 3rd party lense have higher quality ratings than original branded lenses , and often come in a lot cheaper as well if you start looking at your f2.8 range of zooms and some macro's.
The best advice i will give you is buy for your pocket firstly and secondly buy for your need or area of interest.
An average mid range camera with good lenses will work as well if not better than an up market camera with poor lenses.