OK so all of my lenses (rangefinders, mostly) are fairly old: Zeiss-Opton and Leica. I haven't done any comparisons but the difference in contrast doesn't really stand out. I scan (a sin here?) my negatives mostly and print my few favorites. It works out fine, i guess, but I'm not that good in the darkroom or meticulous about my metering/developing/scanning/printing.

Well for certain focal lengths/speeds modern lenses are more practical (Zeiss and CV mostly). The general agreement is that for b&w film low contrast is preferable, but does it really make that much of a difference?