The Optima Gold Rounds are a warm string with lots of punch and clarity. They have a significant bottom end and smooth top end with minimal zing and sizzle. The Unique version that I installed on this bass also appear to have a higher tension than the normal Optima golds I use on my other basses. For me that translates to faster right hand playing but more concentration needed on the left hand to ensure good fretting technique.
The tone across the strings is balanced exceptionally well, which I find is hard to get on my other TBirds. My others (and same with this bass pre Optimas) had a very bright G string, almost to the point of it sounding like a completely different EQ when going from any of the other strings to the G. In the past there were many times I'd slide down the D string for higher notes that I would have normally just stayed in position and played on the G string. Not any more. Harmonics and chords ring very true and sound crisp and clear, not muddy and no chorus effect or competing overtones.
Three interesting things to note vs the Chrome Rounds I had on this bass before the Optimas - I had to add noticeable back bow to the neck to compensate for the higher tension, which was creating a much higher action than I like. I had to drop the bass side of the neck pickup down to compensate for the much louder E and A strings. I assume the core on these strings may be larger or possibly the material more prone to magnetic pickup than the Chromes, thereby making them sound louder. And lastly, I had to drop the bass side of the three point bridge to compensate for the overwrap on the ball end of the string that extended just a bit beyond the saddle (more a function of the bridge design vs the string design).
Overall I'm very pleased with the sound, playability and look of strings. For some it might be too much bling on a bass but for me it completes the picture on this particular bass, which for a stock Gibson is already on the blingy side due to the gold finish, gold hardware and gold logos. Heck I'd put gold covers and trim rings on it if I could find a set - in for a penny, in for a pound. Which brings us to cost. At $70 a set, these strings aren't cheap but they do last a good long time. I don't have acidic sweat problems with any of my strings, but if you do they might be a string to try. The gold plating lasts forever (as far as strings go) and don't flake, peel or tarnish over time. I get between 1 and 5 years on a set of these vs 3 to 6 months out of a set of Chromes. Here in the states you can get them from JustStrings.com (unfortunately BassStringsOnLine does not carry this brand).