I have noticed that many amp designs have remained unchanged for 10 or so years with no tweaks or improvements, it seems frozen in time. Woo audio, Ray Samuels and Mapletree, for example have many older amp models. Now there are a lot of newer designs at the same or cheaper price like Schiit and iFi. Are the older designs still worth the money? Is it like buying a 2005 Honda Accord vs a 2017 Accord? Where all aspects are improved? Are designers driving the same performance into lower and lower price points? Is it sensible to even consider a Ray Samuels or a Mapletree if you can get newer designs for cheaper with just as good reviews and more wattage output ?