As I noted, I've found many multi-dial combo locks to be relatively easy to defeat. I don't see them as being particularly secure.
Agreed. Not a good choice.
Tubular pin locks are more difficult to pick than standard straight key locks, so they provide an additional layer of security in a quick access cabinet or a car vault.
If it comes down to picking, no tubular locks aren't more difficult. Heck, when I was younger we'd impression them with appropriately sized ballpoint pens. The newer tools are better and faster but tubular locks are not in any way an "additional layer of security" over any but the absolute worst pin tumbler or wafer locks.
If you're strictly talking about a quick access cabinet or car vault then sure, tubular locks would be fine. But so would any halfway decent pin tumbler. There are a variety of other lock designs out there (dimple keys, disk tumblers, etc) that would work in that application as well. Hell, in that application an electronic/biometric option could be just fine.
Tubular pin locks are more difficult to pick by hand or by bumping them. Impossible? No. But I've never been able to open a tubular pin lock with an Xacto knife the way I have been able to do with a traditional pin or wafer straight key lock.
There are absolutely some total crap pin/tumbler locks out there, but that doesn't make tubular locks inherently better.