I think topics like this are very intersting for the marketing department from Canon....
Well I made a decision and I went for the 5D with 24-105 and 70-300DO.
I must admit that I have had some *sleepless* nights about this subject...
>Full frame or not
When I have a look at my computer stuff, I see a lot of things that are still working but simply can not be used anymore because it's outdated and incompatible with newer stuf. I dont wan't this to happen with my lenses, although I must admit that it seems that Canon is serious about EF-S.
However if you want to have the full bennefit of Canons (L) lens line up, then full frame is the way to go. a 24-105, 16-35 f2.8 or a 24-70 f2.8 are simply not made for cropped sensors. a 16-35 or 17-40 f4.0 are very wide lenses on a FF sensor, but just normal on a cropped sensor. a 85/f1.2 prime is a nice portraid lens on FF but becomes a bit long on a 1.6 crop body....just some examples.
So when you are more orientated on wide angle -like me- then FF is a good idea is my opinion...but who am I
Yes a 5D with 24-105 is larger and heavier then a 350D + 17-85 IS. But the weight difference between a 30D and a 5D is very small and a 17-55 f/2.8 is about as heavy as a 24-105 L.
If you wan't a more professional camera, the weight of your gear will increase quite a bit.
I personaly like the beefy feel of a 5D or 30D. Both camera's have about the same size and weight and you realy have to look twice to see the difference between the 5D and 30D. When I am on a day trip, I always cary a small back pack, so 1 kg more or less is not an issue. BUt I admit I will not add those white L lenses to my gear, because it's to expensive and heavy.
Never look through a 5D view finder if you do not intend to buy a new body. The difference compared to a 350D or even 30D is huge. Using the 350D it's almost impossible to use manual focussing because everything is so dark and small. The 5D however is bright and large, so it alows you to see what you are doing when playing with the DOF for example.
I have the 5D only a few days so I can not say much about it. The amount of detail on you screen is huge. The ISO performance is very good it seems. I did some tests, shooting images from my beige coloured computer housing, especialy the shades (standard colour for computer cases). This colour makes noise easy visable. At ISO 50 there is no noise at all even when viewed at 200%. Even the levels at ISO 1600 are very low and depending on your demands and how large you print still very usable. ISO 3200 can save your day, but with a quality penalty.
I am to unexperienced to judge about this, but my 35 f/2.0 prime was a dog on my 350D. 75% of my images were soft because of inconsistent focussing. I had to stop down to at least f2.8 and for safety even to f4.0 to get a bit realiable results. When using this lens on the 5D, each image is sharp, time after time..... If this a full frame issue or a better AF control, I don't know... you may tell it. These FF lenses were made for FF film cameras, not for 1.6 crop bodies.
I am running a 3.2ghz P4 system with only 1 GB memory and I don't have any problems with the larger files. Ok it's somewhat slower but not significant. The jpegs are around 6mb while raw files are about 12-15MB. Only my Epson P2000 photo viewer is having a hard time with these files. The P2000 works ok, but scrolling through the images takes much more time.
The 5D lacks shooting modes like landscape or portraid, but I use Av or or M mode more and more. I like to know what I am doing, but the 5D more or less forces you, more than a 350D or 30D.
Just like the 30D it has spot metering, which is helpfull I think.
...uh other subject please...
I sold my 350D + 17-85 for E900,-. The 5D with 24-105 IS costs E3599 and I get E300 back from canon. Currently there is also a E100,- cashback for the 70-300 IS DO.
It's still a lot of money, but considering this is a full frame profesional camera makes things a bit less painfull.
The prices over here (Netherlands) are; 350D (E659,-) 30D (E1199,-) 5D (E2675,- excl E300,- cashback)
Both lenses are very well built, both seem very sharp. The IS on the 70-300 IS DO is extreme good, but as expected this lens seems prone to flare, much more then the 24-105. Using the 5D this will already show up when looking through it's view finder, so you will not be surprised when you arive at home. Until now I couldn't detect any weird things about the DO. It's center sharpnes and contrast is good, but it is softer in the corner. The 24-105 shows some vignetting at the wide end when used wide open. The DO doesn't show any vignetting.
But for the rest I can not give more comments about these lenses since I have to take them into the field first.
During my holiday within a few weeks I will defenately have a lot of fun with this system, and hopefully also the years to come.
....by the way I find Micheal Reichmann reviews and opinions about photo gear very usufull. It's not so much about pixel peeping, but more about reallity...