I have been giving S&S a careful read, for a rules set that is essentially Basic D&D and Star Trek, with the serial numbers filed off, I am impressed with Starships and Spacemen. It has a lot of value for the money, the rule mechanics are slightly streamlined and rationalized compared to the basic DnD rules, it adds a nice psionics section in lieu of magic rules, the THACO calculation is unneeded because they reversed the to hit system, now you just roll under the enemy's armor value. This would save a lot of time with tables and charts.  Monster has Armor class 7? I just roll 7 or less and I hit 'em! There is a bit of humor too, for instance two or three pages are devoted to random forehead generator, a d100 table of little forehead appliance sketches...