I recently bought the Roadster screen and the answer to your question is.... That depends upon what you consider 'worth it'
Here's what I like and don't like about it and then you can decide for yourself...
I Like...
(1) the ruggedness of the mounting.
the mount for the screen is very stout and doesn't flex very much at high speed (80-90 mph)
(2) the ease of assembly
I put the screen on myself and it was very straightforward.
(3) it looks good
Many of the 'generic' screen that would 'fit' the R3 were garbage. I made a $100 mistake buying a 'generic' screen that would have taken a lot of 'modifying' to make it work.
I don't like...
(1) the height
I have it mount and adjusted as high as it goes the wind hits me dead in the face. I'm 5'10". It would be next to impossible to ride in an open-face or half helmet... full-face only
(2) the removal
If you want to take the screen off for the day, it's a pain in the #$@. It has to be disassembled to get off, there's no 'easy' way. Some aftermarket screens like Memphis Shades provide very easy ways to quickly remove the screen.
The prices of wind screens are pretty consistent between $500-600 dollars for a good quality screen. Choices for the R3 are pretty limited.
There have been several postings about alternative screens to the factory model. Search the R3 forum and you'll find links to vendors.
The least expensive vendor that I found was ClearView
http://www.clearviewshields.com/shop/product.php?id=62
