For me, if it's cold enough for tights (usually lower 40's F or colder, depending on wind) then it's cold enough that I'd appreciate another layer on my lower half, so I prefer tights (over bib shorts) to tights with pad. I also like the flexibility of mixing and matching bib shorts/knee warmers/tights/windfront tights, depending on conditions. At 50 I'd still be in bib shorts with knee warmers, I wouldn't even have toe warmers yet.
(OTOH, at 50 deg my wife would have booties, windfront insulating tights, wool base layer, insulating layer and windproof layer, so I understand that different people have different needs with respect to protection from the elements.)