I have a D70, and while it is a very good camera, if I were to do it a gain I would go with a cannon g10. Some of the drawbacks in my opinion with the d70, especially for modelling are:
1. difficulty to get good focus even in manual mode (because of the viewfinder, its not like the old slr viewfinders with ground glass, just clear), where with the G10 the lcd screen zooms in on the area you want to focus, so you know its sharp
2. On the D70 you don't shoot with lcd screen, just through the viewfinder, which I didn't think would be a big deal, but it is fairly annoying, and takes away from easiness of use
3. The cannon g10 default lens has a better range for everyday and macro use.
4. The g10 is much less bulky and easier to use discreetly (for use when travelling etc)
The only drawback to the g10 I would say is that it doesn't have as many lenses, but then again how many do you need? One of the reasons I got the Nikon was so I could use my old nikon lenses on it (I've been shooting nikon since the FM), even thought they are all MF. But one thing I didn't realise, is that since the sensor in a digital slr is smaller that 35mm film you don't get the same image area with those lenses as you would be used to. So I haven't used them at all, just sticking with the default lens (which is excellent though)
Like I said I have a D70 which I use alot at home, but at work we have the g10 and it really is a better camera IMO, and I don't know the exact specs on the sensore, but the image quality and color range seem noticibly better with the cannon
Hope this helps!