Rich, my outlook on semi scale is it that it is much closer to actual scale than traditional PW stock. In reality I call Scale stuff "pretty much scale". Hard to find anything that is dead on and you can run it trouble free it on your layout.
Watch it or I may suggest a Semi-Scale forum 
Words seem to achieve acceptance through use by the speaker and understanding by the listener. It's all a gradual, organic development of communication. Words and expressions from just a century ago can need translation.
If you want to say scale is limited to dimensions only then think of wheel tread, rivet heads, grab bars, rail gauge, step treads, coupler size, tanker couplers, flange size, guard rail gap, frog dimensions, track joints, rail shape, spiral easements or not, super elevation or not, truss bridge sizes, box car door rails, turn out numbers (#5,6 &7.5 are trolley sizes), grades, switch machines, etc, etc. It's usually all NOT SCALE. If all this was scale sized a layout would be in constant chaos.
In any event I love my Sunset scale brass locos, my die cast engines, my smoke and sound PS-2&3 engines, My 2 and 3 rail Lionel engines, couple of odd ball pieces, any car with steel wheels, DC, AC or battery RC. and my child hood 726 Lionel. It's all good.
Nothing happier than going downstairs and running my recent stuff and my 1950's stuff. I let the 3 rail trains run from town to town on their own while operating the 2 rail peddler freights and commuter service while dodging the name trains.
The only scale which really affects my life is the one which records my calorie intake.
It's all good...enjoy!
