I had to chime in....
NOW - please - allow me to slip on my flame proof suit first, and test it....
.... I've always been a NIKON snob. Been so for a long time and used to take great emotional pride in my equipment - and my hobby craft. That was 30 years ago.
After a decade of working, slaving at mortgages, and now starting a family with 2 young kids - I rediscovered my old passon for photography - only today it's gone digital. And it is a wonderful brand new world in many ways.
A few years back I think most would agree it was a knife fight with the early DSLRs. Nikon and Canon were the big contenders for dominance... and most would not deny that Canon has emerged the big winner. On
Amazon their top 5 DSLRs are all Canons (11/4/2006):
http://www.slrtoday.com/articles/10...inate-Digital-SLR-Bestsellers-List/Page1.html For several years Canon has sold more DSLRs then all other manufacturers combined. And only recently has Nikon been able to say they now sell more DSLRs then Canon .... in Japan (only). In fact, it was only in the month of December for 2006 supposedly...
http://www.studiolighting.net/nikon-dominates-japan-dslr-market-canon-400d-still-no1/ And here is an unscientific representation of brand and model specific interest in the market among DP Review ENTHUSIASTS
http://www.dpreview.com/reviews/stats.asp You'll note the top 10 have 8 Canon models represented - and Canon as a brand gets more click through interest then the next 3 companies combined : Nikon + Panasonic + Sony.
That said... I think the guy in 2nd place works harder for your attention - and I admire certain aspects of the Nikons over the Canons. In particular - the fit and feel - plus some aspects of the handling qualities. While on the other hand I would say Canon has had a full frame DSLR body for 5 years.... and only now is Nikon emerging with thier first full frame DSLR at roughly the same resolution as Canon had 5 years ago. Now thats' not the whole story because the new Nikon has new features the old Canon did not have. But it HAS been 5 years. Technically... you might think Nikon is technically 5 years and 2 generations BEHIND Canon in strictly sensor size and resolution in their TOP OF THE LINE bodies.
So ... WHY is it that Canon sells more bodies then everyone else combined? Is it marketing? Is it obvious technical superiority? Is it the lens selection? DO folks buy bodies according to the alphabet - hence stop and buy at "C" before "N", "P" or "O"? In the most recent full year 2006 Canon had 46.7% of all
DSLR sales compared to Nikon with 33%. Overall - Canon was #1 with 18.7% of all D camera sales and Nikon was #6 with 7.6% of market share. World wide #2 was actually Sony followed by Kodak.
http://www.reuters.com/article/idUST23502820070403?pageNumber=2
I think a reasonable strength is thier early lead with CMOS sensors. The images rendered from the Canons was more desirable post camera then the nikons - with their slightly more saturated and contrasty images. Which some feel are "better" because they require less post camera attention to be visually pleasing - but on the other hand there MIGHT be more image detail lost in having an original image will so much intnesity. NOW... consider - I am NO expert - and only barely a professional in that I've been paid for some of my work - and I am essentially retired and donate the vast majority of my production (that is not for personal use).
So - I think the Canon DSLRs had a technological advantage with their sensors. Especially for full size sensors - and even with lenses. They introduced the worlds first consumer level standard zoom lense with IS... which I believe was the 28-135 IS. Or at least PhotoZone.DE says so....
http://www.photozone.de/8Reviews/lenses/canon_28135_3556_is/index.htm Also, I noticed the Canon focusing systems seemed to be more sophisticated then the Nikons - and that's just me with a peanut gallery opinion.
Now - there are things I'm sure everyone can nit pick. IE, it pricks the imagination to think the IS mechanism could be in the BODY as opposed to the lenses. And I saw a test report in print that suggested the body mechanisms did a darn good job... thus calling into question the expensive Canon approach - which essentially milks us of some hard earned / saved moola. AND... I see Nikons and especially Pentax selling at lower price points then Canon. And that leaves me wondering when (if ever) Canon will drop thier prices or step up some of thier features to trump their hot running competitors.
In general - my friends simply say Canon has the edge in lenses and sensors. Body wise - it's a tight horse race for fit, design and finish. Cost wise - Canons will cost more.
OK... so bring it on. GO ahead and sling some mud - I know it's due me - and remember - I would rather shoot NIKON if they had the edge when I was starting my new DSLR kit. Now that I've invested in a few lenses
I'm officially BIASED and I'll be extremely unlikely to switch - unless I had a really compelling reason. And Nikon does not have any obvious significant advantage.
There really is a lot more in common then different though - for the most part. Some may focus on specific differences as compelling - but the larger market suggests the lead is dominated by Canon for DSLRs - as well as for most of the pocket digicams. You will obtain prety good results with almost any manufacturer and their better pocket or DSLR models. So - step forward with an open mind. You're on thecusp of a fun decision - what new DSLR toy to buy! What FUN!
OK.... my point - I think you should go with what your existing KIT leads you to - and if it were Minolta/Sony ... so be it. If its' Canon - as in my case and yours' - then it's an easy decision. In your case - there is little serious distinction between the two except that you already have some Canon lenses -
which lenses and accesories do you have? Maybe you should go try the two that interest you most.
REMEMBER - Ultimately, the photographer makes the MOST difference... as would the paying jobs and terms you wrangle more then the equipment. Of course, if you're making a living with your equipment then it pays for you to simply get the best that you can get - and you already know what a "cost is no object" decision looks like... the Hasselblad with all your favorite lenses! Yuck - hope no one shoots you for your kit if working in the field! I've had friends who work professionally who have been robbed of thier equipment - and that is NO fun. There should be a special place of torture beyond this existance for camera thieves!!!