Is the Nikon D600 a pro camera?

Is it a lot better than my D5100?

"Is the Nikon D600 a pro camera?"

Hard to say; it's full frame but I don't think it's made to the same standards as the D800 and D4. Probably somewhere between semi-pro and pro.

"Is it a lot better than my D5100?"

Quite a lot better, yes. The D5100 is aimed at intermediate level photographers, and the D600 is aimed at higher level photographers. It has a bigger sensor, more resolution, and almost certainly better low light / high ISO performance.

This is all assuming that the photographer has the skills to make use of the extra power of the D600.

Nope

It is an entry level full frame digital SLR.

Its brother in the APS-C sensored Nikon cameras would be a Nikon D7100.

The only pro (meaning sturdy, totally reliable after over 7 years of hard use) cameras at present are the Nikon D300, D3 and D4.

I'm guessing you are really asking if the Nikon D600 can produce pro quality images. That answer is yes it can, but the user has to have the skills and experience in order to produce marketable images each time they press the shutter release

It really does not matter if you spend $500 for a good used dSLR or over $40,000 for a medium format Hasselblad. The images are only going to be as good as the photographer, based upon some formal education, enough to learn the fundamentals of photography and many years experience shooting many various subjects in just about anywhere in the world or out of it

There seems to be some serious misunderstanding about photography.

* to take better photos, you have to buy a better camera
* all brilliant photos are the result of using Photoshop.
* a photographer must be a skilled user of Photoshop.

A photographers goal is to produce marketable images each time they press the shutter release. Now we're shooting in RAW and processing those digital negatives in Lightroom. In lightroom we can calibrate the image file to match the custom white balance we determine by using a product like Colorchecker Passport and correct for lens aberrations automatically.

Everything else about the image must be ready to publish or print, right out of the camera

I think no.

Interesting question because that's my camera and I chose the Nikon D600 when I found out this:

http://kenrockwell.com/...camera.htm

And this answers your second question:

http://snapsort.com/...Nikon-D600