Well, I see the problem, but then, a search site that doesn't allow you to use effective filters is ... kinda useless?
Though I think there is a more important thing to note here: Maybe you should explicitly support handling of unknown values in the UI? Failure to do so is IMO one of the biggest problems of most specialized search sites.
Sure, there are attributes that cannot always be determined reliably if at all--but instead of either ignoring the attribute completely or forcing it to "false" or "true", or some other explicit value, why not allow the user to specify whether entries for which the attribute is unknown should be shown? That way, if my requirement is proper IPv6 support, for example, I can decide whether I am in the mood to wade through tons of crap, but still have you filter out all entries for which it is known that proper IPv6 is not supported, or whether I want to ignore those and only look at the (probably more expensive) selection of providers that clearly advertise that their product isn't broken.
Though I think there is a more important thing to note here: Maybe you should explicitly support handling of unknown values in the UI? Failure to do so is IMO one of the biggest problems of most specialized search sites.
Sure, there are attributes that cannot always be determined reliably if at all--but instead of either ignoring the attribute completely or forcing it to "false" or "true", or some other explicit value, why not allow the user to specify whether entries for which the attribute is unknown should be shown? That way, if my requirement is proper IPv6 support, for example, I can decide whether I am in the mood to wade through tons of crap, but still have you filter out all entries for which it is known that proper IPv6 is not supported, or whether I want to ignore those and only look at the (probably more expensive) selection of providers that clearly advertise that their product isn't broken.