Well all the modeling algorithms that drive all the current soft synths are based on algorithms developed by software design companies. While they may approach the real thing they are NOT the real thing. Analog circuitry in synths reached its peak in the mid 80s and synths from this period got as good as analog synthesis got. If you want the sound of 80s synths then you should get a synth from this era. The biggest downside is maintaining these old synths as many parts to repair them will either be unavailable or expensive to obtain as they will often have to be pulled from other non working keyboards. The new MOOG Voyager is a good option as it features all the abilities of the original Mini MOOG and is again in production so maintenance is not really a problem.