I wasn't saying they're absolutely not worth it, there are just other considerations. If I was assembling a speaker system I'd more likely buy a vintage Class A Marantz than a Cayin CS55a just based on the price, considering the lowest impedance I'd put on it would be a 150ohm HD660S anyway, which is why I use high impedance cans - my HD600 didn't vary badly in sound between a Marantz CD60, NAD 304, and the Technics vs dedicated headphone amps (if anything, the CMOY was actually the worst, but it's a 9v battery-powered amp driving 300ohms...though later 7.2v battery amps are a heck of a lot better than it). That of course assumes I have to buy the CS-55a online instead of a local dealer that has a tech that can diagnose or facilitate repairs through the distributor. On top of that, the OP was asking specifically about older headphone amps vs newer headphone amps. If the question was a lot more general (ie if he didn't have specific amps in mind) that would be like asking if the Creek OBH-11 which had a good rep in its time would be as good as something with the same or even lower MSRP now (plus, again, there's warranty for buying new, but hey, if it's $50 and somebody just needs a headphone amp for a speaker system with a crappy headphone out on the integrated amp, by all means save some cash).