I have a Kala Rumbler uBass, which came supplied with the standard black strings. This little instrument produces a nice sound, but you really have to work quite hard to get consistent sounding results, and the original strings have a number of drawbacks.
For instance, the low E string does not produce as loud a note as the other strings, unlike a conventional steel string bass. So you have to pluck this string with much more energy, and play the other strings more lightly to get even sounding notes. A compressor helps if your amp has one, but this can sound a bit artificial. Another problem with the black strings is that they appear to be are slightly sticky when you play. They are not actually sticky, it's just their rubbery surface produces too much friction to easily slide you fingers along them to glide notes up or down like you can on steel strings. This also makes fast sections very difficult to play. Perhaps the biggest problem with the black strings is keeping them in tune, because of their stretchy nature you are constantly re-tuning.
You tend to get used to all this when you play a uBass, and adjust your technique accordingly. However, a solution exists in the form of these Aquila Corde strings, and having changed to these, I would never go back to the black strings! The new strings are a creamy white colour, and feel firmer and less stretchy than the black ones. The volume problem between strings is almost completely solved, you still have to work a little harder on the E, but it's much better and the less rubbery feel of the new strings makes them more responsive and musical. It's also easier to play faster sections and notes, and you can just about do some sliding and gliding around.
The tuning stability is much better with these new strings, you will still be checking your tuning every now and again, but not between every song like previously. I have spoken to other uBass players and they all seem to have come to the same conclusion, the white strings are significant improvement on the original black strings. The pricing when buying from Thomann is very good too. There are some helpful videos if you search online which show how best to install the strings, particularly how you tie them to the tuning pegs. These strings will make your uBass much easier and more fun to play!
