I highly recommend, with some suggestions.

I have this wonderful D7100 for nearly two months, and I have done with a few thousand photos, in various circumstances. As to 18-105 mm, I could compare its performance with the 16-85mm on my D90 (which I still treasure).

THE NIKON D7100:

- Piqué and made JPEG (not to mention RAW) beautiful. The sharpness is such that the objectives are starting to have trouble keeping up; and in development and shake, the least blur is noticeable on large prints (70 cm x 50 cm size that does justice to the qualities of D7100). JPEG are very accentuated by default. 100% examined, it can give an impression of softness, which is very easy to remedy, for example by pushing the accentuation of 3 (default setting) to 5 (as I did) or 6.
But in the real world, on large prints, the image is not only extremely piqued, but especially extraordinary luminosity and brightness, impression reinforced by the discretion of emphasis adopted by Nikon: D90 versus a yet very high level, it seems to pass through the 24x36 format.

- In the high ISO, the D7100 is not better than the D90 (it is probably even a little more grainy). But as it is twice as defined in the end the result is better in low light.

- Dynamic (the ability to make both very bright areas and very dark areas) is better than the D90, and infinitely better than the D70. And this, even in JPEG, provided of course compare to a slide, not a negative (it would then compare RAW).

- Further useful functions appear: first the HDR, which extends for once incredibly dynamic (for a stationary subject). But also the "Perspective" function, which allows to replace - and better! - A costly shift lens by adjusting the trailing lines on buildings. And in my case, the presence of an artificial horizon (for pictures perfectly straight) is a marvel, a fundamental improvement. It is very active simply by programming the Fn (via "f2" in the custom settings menu).

- The autofocus is very nervous, and monitoring burst is impressive, while this burst is 6 frames / second and can even go up to 7 frames / second in "reframing 1.3" (autofocus of the D7100 is actually that of the D300). It can be very long burst JPEG (over 50 pictures), provided you have a card 95 MB / s.

- The measure of exposure is excellent, provided you pay attention to the different settings and the precise area where the exposure was measured (for even disconnecting the autofocus and exposure, the camera takes still account of that on which the point has been made).

- To complete the performance review, the video is much higher than that of the D90: one is really in blu-ray quality, having a camcorder advantage of the large sensor (no problem of sensitivity) and management depth of field. By the way, being able to allocate one of the two video cards is also quite practical.

- Finally, the construction and finishing of the D7100 are very serious. It has a magnesium alloy shell (front and top of the unit) as the D7000, but better Tropicalised since Nikon announces that the anti-splash protection is the same level as on the D300 (ie on top ). The shutter is certified to 150,000 trips, and details of the ergonomics are excellent, whether the locking of the two selectors on the left, users U1 and U2 modes, etc.

THE 18-105 MM:

- Contrary to what we sometimes read the 18-105 mm is a high level of optical quality, and is perfectly usable on the D7100. Of course his dive will be lower than a fixed focal excellent, but it's still excellent.

- However, although it is more expensive, I still advise to seriously consider the purchase of 16-85 mm: the difference in quality does not will burst the eyes, even on large prints, but the construction of 16 -85 mm is much higher (it was designed for the D300, a semi-pro, while the 18-105 mm was provided for the D90). For example, in very heavy use, the plastic ring located at the end of the zooming ring can take off on the 18-105 mm, then we will have nothing like the 16-85 mm.

- Also on the photographic plane, being from 18 mm to 16 mm is precious: we are left with the equivalent of a 24 mm in 24x36, allowing more dramatic photos, with more dynamic rendering while making possible the views not possible with 18 mm recoil fault.