Just to expand on your posting:
There is a lot of material on these topics on my "Icom" page.http://www.qsl.net/ab4oj/icom/icom.html
The following links are relevant to this discussion:
Basic Concept of Icom IF-DSP
George, W5YR's articles on occupied bandwidth, the Monitor and Filters & DSP.
IC-756Pro User Reviews (yours and mine)
There is no balanced modulator in a DSB-based SSB transceiver. The speech amplifier drives the analogue/digital converter (ADC), which digitises the transmit audio. The DSP processes the resulting bitstream. The digital/analogue converter (DAC) converts the processed bitstream to an analogue IF signal, which is up-converted and amplified for transmission. The exact reverse process takes place in the receiver.
The DSP generates SSB by mathematically modelling a phasing-type SSB exciter.
DSP is not only here to stay; it allows radio designers to achieve levels of performance and functionality unattainable with analogue designs. With the advent of faster and cheaper ADC, DAC and DSP chipsets, DSP radio architectures have also become significantly more cost-effective to implement than analogue solutions offering the end-user far less in terms of performance/capability.
Check out the Icom FAQ site: http://www.qsl.net/icom/