Generally you want a narrower Q.

Though I've got a set of old Sakae cold forged cranks that when mated to my track bike's BB seat so deep that I have to move the ring to the outside of the spider to get a proper chain line. The cranks have very little flare from the spider, so I'm basically looking at like a 45mm-from-center tread and that actually feels too narrow for me to get decent power.

Modern cranks have much higher Q factor, both because they're designed to provide clearance for bikes with wider rear triangle spacing (as much as 140mm on some mtb's) than old road (126mm) or track (120mm) bi kes. On top of that, cold forged allows for a slimmer profile than the less expensive manufacturing techniques that are popular now.