I did compare my old 90 dbx chip pedal to a 2000 THAT chip pedal. I noticed that the newer pedal sounded a lot cleaner, the old one has an almost tube drive quality to it, and while the newer pedals aren't bad at all, I just dig the sound of the old one better. It should be noted that I use it exclusively with bass guitar, and I get the same results with the pedal in front of the amp and in the FX loop.
Plus the fact that I'm used to it, after using it for 14 years, I bought it 2nd hand in '95.