There are so many cool plants available - anymore. I've always thought this was cool-looking since the first time I found it on the net... too bad it's sold out or I'd have bought one.
Acer saccharum 'Barrett Cole' (Apolloâ¢) Returning back to your questions above, Google shows us every nice examples of both - Slender Silhouette is much more dense and much more pillar-shaped...... as we know, that's not to say it won't open up when become floppy when they're, old. How long it's been around, for evaluation, is the key that unlocks the door - to the answers of your questions... an example of such is, Pinus strobus 'Fastigiata'. Mature trees now show us that this grafted cultivar becomes very wide as it reaches the 40+ foot range. The branches instead of staying fastigiate literally open up with age...

Regards,

Dax

Here is a link that might be useful: J Frank Schmidt and Son

When you read about a new tree nobody outside of the originating entity or the place where it was discovered growing is going to have an old one yet. And often they won't either.

When a cultivar is based on an already large specimen then descriptions of that one example may be available.

Hi bboy, for your knowledge... Dennis at Bethlehem nursery told me that Pinus strobus 'Stowe Pillar' was found as an old tree by Chris Trautmann - and that it is 'one of the most amazing trees'. I bought a couple without knowing this for pennies on the dollar, literally. This cultivar will be without fail, fastigiate. And there are no concerns, ever, for snow loads splitting the structure.

Dax