Old verss new Dacs

What are the virtues of a new dac like a benchmark versus an older high quality one like a krell studio or studio 2? I really like the look and feel (in addition to sound) of the krell stuff but wonder if I am missing out using a krell studio 2 dac rather than a newer one. Thanks for any thoughts.
Depends on how old. I had an old Theta 18 bit that was great in it's day but can't stand up at all to a new mid-level cd player with 24 bit (music hall or cabridge). The new ones are definitely clearer. Also got rid of my CAL Alpha once I got my MH modded.
I have an older DAC as a spare (McCormack DAC 1 Signature) which cost me $600 new and has served time in a second system. Like you, I am impressed with its build quality. Its sound is warmish, yet detailed enough to satisfy. I've no problem putting it back into duty in my main system.

All comes down to your preferences.