I shot film for a long, long time. It was my job for a while. I owned and used Canon, Graflex, Kodak, Nikon, Olympus, Yashica, but never a Pentax. Post-film, I owned and used Minolta, Olympus, Sony. Just over two years ago I decided to buy a dSLR. I've trained in systems analysis, so I did extensive research, crunched numbers, drew charts etc.
First I looked for the lenses I wanted, that I could afford -- and my best options were Olympus and Pentax, even though I was given some nice Minolta lenses that were usable on a Sony dSLR. Then I closely read user ratings at
dpreview.com and especially noted the bitches and gripes, the comments about wanting to upgrade ASAP, etc. That's what drove me to Pentax. Users of cameras comparable to the Pentax K20D were *not* happy campers.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
There is a demarcation line between advanced and professional photo systems, that has less to do with cameras than support. Canon and Nikon (and Mamiya and Leica and Hasselblad?) maintain extensive and expensive support networks for pros whose livelihoods depend on functioning gear. Pentax is building such a network for their 645D MF camera, starting only in Japan. These larger format (FF and MF) cameras are NOT like anything sold at BestBuy or CostCo or WalMart.
Yet much of Canon/Nikon's mystique is that their cheap plastic consumer crap is somehow associated with high-end cams that cost more than autos or even houses. Yes, Canon/Nikon make superb gear. No, it doesn't always work right.** No, you can't afford it. No, what you CAN afford isn't much like that expensive stuff, it just has the same logos. Hey, it's a marketing scam! Bait and switch! Look at this 5D Mk II! Hey, take this Rebel instead! Feel the magic! Right.
**
A pro complained to me that his new FF Canon, at maximum FPS, sprayed oil on the sensor. It took five trips to the Canon shop to get it repaired, with some redesign, he said. It's hard to make a living when your main tool is in the shop.
Previous comments apply. Someone pushing a particular system is selling and/or lying and/or ignorant. Modern dSLRs are wondrous devices; nearly all can deliver superb images, IF USED KNOWINGLY. And nearly all will be junk in just a few years. The longevity of modern plastics (and optical resins) and electronics is questionable. Some of us use photo gear that's a century old. Will that 5D Mk II still be functioning in ten years? Will it be laughably obsolete then?
Whatever. It's only money. NOTE: Many of those high-end Canikon FF's are used for sports or celeb shooting, and their output is printed in slick mags and pulp tabloids of lesser (not to say crappy) image quality. A 5mpx P&S would provide images that are just as suitable. Dig out that old bridge superzoom and you can be in National Geographic and Sports Illustrated (and Hustler) too, eh?