I grew up on these rules. They are rather interesting, and may take some getting used to, and I may be very nostalgic, but I very much loved playing with this rulel set. It will do many modern and sci-fi settings without a hitch, and I believe that there are numerous modular rule sets by fans that make this an excellent starting point for many great campaigns. Look for the rules light version, which I believe is still free, and come get this rule set for $4. It is totally worth it.
[4 of 5 Stars!]