The Hasselblad CW (also known as the Hasselblad 503CW) is a part of the V-system of cameras and was developed by Viktor Hasselblad as a flexible camera system.
The bodies, lenses, viewfinders, winders, film magazines, holders and other accessories are all meant to be interchangeable.
The name "V-System" wasn't really used until the "H-System" was developed.
Using the name "V-System" is an easy way to note the older product line.
(The H-system is digital-based.
) And now, here are 5 reasons to love the Hasselblad CW:

1. As mentioned, this is a flexible system.
   All parts and pieces from the V-System are meant to work together.
   That means that your photography is more flexible too.
   
2. The 503CW has the ability to use a motorized winder (the CW Winder).
   This gives a film advanced rate of 0.
   8 frames per second.
   
3. While the CW Winder adds a lot of size and heft to the setup, it's quite pleasurable and easy to use handheld.
   
4. The Hasselblad CW uses through-the-lens (TTL) metering, making things extremely easy for those who use flash often.
   
5. One review I read quoted it to be "the perfect camera.
   "

If you decide to go with a Hasselblad CW, you are going to get outstanding photos.
In fact, in another review that I read, the reviewer mentioned that between the 503CW and another camera that he owns, the Hassy's photos stand out every time.
Now, part of that reason is the quality of the Hasselblad camera body.
And the other part is due to the superb Carl Zeiss optics.
Yes, Hasselblad cameras are very expensive, but from what I've read, I haven't found someone who said it wasn't worth it.
If you're a professional photographer, you need to have professional tools.