20 years isn't old for well-designed, well-made equipment. I'm still very fond of my V3. The ultra-low distortion, the low-cut options, the high input impedance and input headroom, the predictable and repeatable gain settings, the metering--all are just about perfect for me / the type of recording that I do / the mikes that I use.
A few years back I bought a Sound Devices MixPre-D to replace it--smaller and of more recent design--but I just couldn't "feel" it, and I never used it. Plus if I recall correctly, it had a somewhat awkwardly large amount of gain in its input stage and might sometimes have needed external pads at the inputs. That's sad when the first thing after those pads is a pair of built-in step-up transformers! It just gave me a less than ideal feeling, whereas the V3 gives me no bad feelings of any kind.
That said, for purely analog situations I have a Sound Devices MP-2 that also gives me no bad feelings of any kind, and I appreciate that it's so small and can run on internal batteries for hours. It's just for a different application, is all.