Justin Oscar Cary, a bassist based in Nashville, runs a nice blog featuring gear reviews and other ramblings about the bass and being a professional bassist. It’s worth a look if you’re into playing bass.
He recently posted a review of the Aquila Thundergut strings for the uBass. He even posted sound clips of the Thunderguts and of the Thunderguts vs. the stock Pahoehoe string. It’s well worth a read.
According to Justin’s review of the Thunderguts:
The sound is very similar to the Pahoehoe strings, however the Thundergut has far more treble detail and more acoustic volume. The volume from the instruments pickup is also a touch louder.
He concludes that the Thunderguts not only give you a bit more volume, but they are
much more stable and stay in tune better than the Pahoehoe strings.
Tuning stability is probably the greatest benefit of the Aquila string. My set of Thunderguts took only minutes to install and reached tuning stability in only 2 days! Tuning stability has remained at least 50% better than the stock strings.
He even shows you how to install the Thunderguts on a uBass (hint: don’t lose those red grommets on the ends of the Pahoehoes).