Hickory,
I used the original black one for about 5 years, and the only pedal I swore I'd never part with...until they made the red one. It does look a a lot cooler, unless you prefer low-visibility pedals, which I did for a time. With the new yellow LED, you will never wonder whether it's on or running low on batteries.
The original reason I got this pedal was to increase the sustain on my archtop so I could play riffs in unison with the sax player (e.g. Herbie Hancock's Actual Proof) with out loosing the guitar's punchy attack. It does that better than any other pedal could, but as you know it is quite a versatile pedal, and over the years I found the best application was as a clean boost with a bit of compression, of course.
Compared to the original, RED can push the amp further into crunchy overdrive. With vintage style single coils, this makes a appreciable difference. RED is also supposed to be a bit quieter, and I suppose it is. Wit h the original, noise only becomes noticeable at high settings, which I usually avoid. This is probably the same for any compressor, though.
Please note that I had them install a B-Buff (buffer/booster) in this pedal so that it is always on since the Tonepress is the first pedal in my signal chain. The buffer adds a bit of of high-end sheen I sometimes felt the original was lacking, and can change the response of compression when goosed. So I can't really make a totally subjective comparison between the two pedals.
However, I did try to A/B the RED against a Barber Launchpad (same circuit) buffering the original Tonepress, and they sounded almost identical. If I did feel any preference toward the RED, it was probably because I can't admit to myself that I just spent almost twice as much on something I already had because it was offered in a different color which is not even one of my favorites.
By the way, the B-Buff takes up the space normally reserved for the battery, which is actually a bit inconvenient for me. Something to consider, if you're thinking about getting that mod/option done. I found out the hard way.