It is incredible all the sounds and nuances you can get with this little pre-amplifier for bass, from SVT amps to an infinite range of options playing with every parameter. The most interesting thing, in my opinion, is that you can preserve as much as you want the original sound of your bass, and there is even a LPF for the dry signal to keep only your dry low freqs.
Apart from the cabin simulator (which is quite realistic) and the other features like the semi-parametric equalizer, there is a gain pot which can get you a perfect tubey distortion/saturation if you crank it up. Besides, it has a headphones volume control, which I have not found in any other pre-amp pedal similar to this one, and the sound quality of the AUX input is excellent too.
The only downside I have found, though, is that in the semi-parametric equalizer, if the 1.5 kHz for high-mids is selected and turned up to the maximum, there is a loud whistle (perhaps due to my headphones resonance frequency, or maybe due to some kind of feedback I do not understand), but I cannot consider it a real problem, since I will not increase that range of frequencies that much, really.
All in all, the Simplifier is a great improvement for my bass and I can only recommend it! Good for practice, for recording, and for gigs :D
PS:
By the way, the instrument I am using is a passive Precision bass.