The megapixel rating is only one small part of the end result of a good camera.
To be truthfull only Nikon or Canon have got the 'breeding' and technical know-how to produce good cameras. All other brands IMO have at least one major flaw in their package.
I tried loads of cameras before i settled on my Nikon and i already knew roughly what i was looking for having done a HND (Higher National Diploma) in photography at college in my youth!
Most other brands have not had the opportunity to iron out some major defects in their packages. Build quality is one major problem, buttons and dials feel slack and flimsy, buttons are in places that mean they are accidentally activated or can be caught and broken off. Lens design is totally different to film cameras and only the "big 2" have yet acheived good quality lenses.
Pentax was a good brand and many of my fellow students had their film SLR's when i was at college, but this was after 30 years of development and catchup from when SLR's started to become popular in the late 60's and 70's. By then Nikon and Canon were still the established benchmark cameras.
With regards to 'bombproof' no modern SLR digital or film is that. The older manual SLR's were very rugged (indeed there is a Nikon FM2 in the museam of film and tv in bradford that stopped a 7.62mm bullet in Vietnam!!!

) but no modern camera would benifit from being dropped.
To get excellent results, fantastic range of accessories (original and third party) a reliable dependable camera there is really only 2 choices Nikon or Canon. I have owned both over the years film and digital and the only thing that should influence your choice of either is the range of features, price you can afford and which 'feels' best in your hands.
PS just to confuse matters some cameras megapixel rating is "interpolated" (do a google on that it would take too long to explain and there are better people than me who can do it) so 6.1 megapixels could in reality mean 4 megapixels. Nikon and Canon are "true" megapixel rated.
Sorry to confuse you further
