Crystal Clear III does not include a comb filter, although some Philips leaflets erroneously state the opposite. In some of the 100Hz sets though, the digital processing suppresses cross-color artifacts a bit. The resolution is not improved by this processing.
However, in actual moving footage I don't think there is a major difference in performance with and without comb filters on Philips 100Hz sets (on my set regular off-air TV actually gets a little sharper when I turn the comb filter off in the demo menu).
With S-video input a comb filter would be bypassed, so the absence of it in Crystal Clear III does not impair performance so long as you use S-video for your S-VHS VCR. Being a S-VHS VCR it might well have a comb filter itself, improving signal separation before recording.