Actually, you can get some really great bass sounds with the Tempest. It's one of its secret weapons in my opinion. While you can have a 3 or even 4 oscillator (as in traditional sine, triangle, square, saw wave) bass, it is possible to utilize the drum samples creatively to get a nice sounding attack going.
Older organs have that key 'click' that helps define them-- and it's often considered as a feature that you can turn on or off. With the Tempest, not only can you create a 'click', but you can also control the timbre of it!
It is also worth noting that oscillators 3 & 4 have a separate routing to the filter that allows one to mix the non-filtered sound wit the filtered sound, so you can have analog oscillators affected by the filter and digital oscillators completely unaffected (or however much you want!). Not only that, but since the Tempest has 4 envelopes, you can give oscillators 3 and 4 their own separate envelopes.
Food for thought, anyways