Our group has had this discussion many times. It seems unrealistic that a country would develop something that is not useful.  In one of our games Russia bought a non-disposable tech dice and actually rolled a 6 then rolled on the chart and got “War Bonds” which was cool for them but if you look at the list there are very few that Russia can benefit from.  Mostly depends if they are on the offensive.  If they are on the defensive then only “War Bonds” and “Increased Factory Production” seem to be worthwhile.  “Radar” would also be good but its on a separate chart with tech that would not benefit them.  Most would say that Russia should not even consider rolling on tech and I tend to agree unless they are on the offensive and have a massive economy.