I will not participate in the emotional discussion about sine waves but want
to mention some technical details (some of these have been already mentioned
earlier):

All standard VCO circuits I know are based on a sawtooth or triangle core.
When the sine wave is derived from one of these VCO cores you will never
obtain a perfect sine. The antiparallel diodes are the simplest solution to
derive a sine-like wave from a triangle, the FET circuit is a bit better but
even far away from beeing perfect. Each kind of waveform converter is a
compromise (except rectangle). If you want a perfect sine you need a VCO
with a sine core. And in return: if you want a perfect triangle you need a
VCO with a triangle core, if you want a perfect sawtooth ...

The A-143-9 is the only oscillator in the A-100 that uses a sine core.
Though it was not planned as a VCO but mainly VCLFO it can be (ab)used as
sine VCO. The main drawback of the A-143-9 is the missing temperature
compensation of the exponential generator. We consider to develop a sine VCO
based on the A-143-9 circuit but with a temperature compensated exponential
generator. I expect that the price would be in the Euro 100 range. We are
also working on a VCO with sine core and linear FM with thru-zero feature.
But this is another "construction site" because the linear FM and thru-zero
feature is much more complicated than adding "only" the temperature
compensation.

And we will point out in the module information and user's guide of A-110
and A-111 that the sine outputs should be called more precisely "sine-like".
But even rectangles or triangles are not perfect (each rectangle is kind of
trapezoid as each rising and falling edge has a slope that depends on the
inherent slew limiting characteristic of analog circuitry).

Best wishes
Dieter Doepfer