The very best systems I've heard were primarily "vintage," but this term is not easily defined and can be more complex than simply the age of the component. These systems were new builds, but most of the components of the speakers and the electronics were very old, some going back to the 1930-50's. Some of the speaker drivers were "new" but essentially replicas of very old drivers. The new drivers were G.I.P. Laboratory (Japan) reproductions of Western Electric field coil drivers and an "updated" version of a Western Electric tweeter (the tweeters alone, without the field coil power supply are $60,000 a pair).
My own system is sort of the same sort of mix of old and new. The linestage is based on an old Western Electric design and utilizes Western Electric transformers, but it is a new build with remotely controlled volume control. My amp is also a new build based on a Western Electric amp and utilizes the original design's input and output transformers. It also uses a lot of other vintage parts--old Aerovox capacitors, old flat resistors, and the original Western Electric 348 and 349 tubes, but the power supply transformer and choke are modern. My speakers have have modern, but old school woofers (twin 12" alnico magnet drivers with pleated paper surrounds), a modern Fostex bullet tweeter, and a very vintage Western Electric 731b midrange compression driver and a Western Electric 12025 multicellular horn.
In certain areas of sound quality, these old school and vintage systems have not been surpassed, but, in other aspects of performance they generally don't match new speakers (bass does not go as deep and with as "tight" a sound).
As to any kind of "risk," it again matters what kind of vintage gear one is talking about. Old tube gear is quite low in risk to invest in because all of it can be repaired easily and maintained for a very long time. That is not often the case with solid state gear that is 20 years old and older--some replacement transistors and chips are almost impossible to find and people who can diagnose and repair complex solid state gear are hard to find. A lot of vintage tube gear has been pretty much depreciated to the point where they may no longer lose value over time. Some such gear actually appreciates in value; the Western Electric parts I own only keep going up in price, and some of it quite dramatically.
