I am considering a fork upgrade (?) using Martec M3 from chucksbikes:

http://www.chucksbikes.com/store/fo058.htm

The weight is actually 580g (!!). Currently I have cro-mo fork from early 90's on the bike. I am guessing it used to be pretty high-end since the bike has Suntour Superbe Pro for drivetrain.

What do you guys or gals think? Is this a worthy upgrade? Do you have any other suggestions for 1" threaded carbon fork that is inexpensive yet somewhat good?

Thanks very much in advance for your help!