What makes for a good scale of around 19 notes?

A scale of this size is not something which can really be grasped as a
gestalt, and if one wants to construct good examples, one first needs
to know what a good example means. For instance, in the Scala archive is
something called "smithgw_18.scl". This has five otonal and five
utonal tetrads, and if you temper it via marvel, that goes up to six
otonal and six utonal tetrads. This is pretty good for 18 notes. Is
this a good scale? It is not epimorphic, and adding notes to it to
make an epimorphic scale requires one to go up to 27 notes, which is a
big difference. However, the ratio of largest to smallest step size
(3.19) is not terribly unreasonable. The scale is clearly more
irregular by various measures than Blackjack, but how regular does a
scale of this size need to be?

I'd be interested in hearing the viewpoints of scale end users.