Dave,
I have the Trekker with the optional carbon fiber poles. Unfortunately I have zero backpacking nights using this shelter but I do have about 10 car camping nights, all under very mild weather conditions.
A set of two poles weighs 3.5 ounces on both my digital scales. The poles are set up against the interior walls. The upper pole tips are captured in a spreader bar while the lower tips rest on reinforced areas of the floor.
(I was going to insert two photos at this point but was unsuccessful. Yup, tried restarting, logging off/on, Firefox, Chrome, 200 k and 75 k sizes).
So far there is no wear on the interior floor from the rounded pole tip ends. One could imagine that there would be less wear and tear on the floor when using the much larger surface trekking pole handles; on the other hand I tend to worry too much!
FWIW I also have a set of Zpacks poles, custom length for a different shelter. They come with rubber tips on both ends and fit nicely into the spreader bar. The Zpacks pole diameter is about 0.75cm. The SMD is about 0.88 cm. The SMD poles have a two stage butt connector, i.e., there is a plastic insert within the metal (aluminum?) insert. The Zpacks connectors appear to be carbon.
I hope this information provides some help.
Slightly off topic. I had to seam seal the apex twice. I *think* water was entering through the grosgrain/nylon loop attached to the interior. A dab of sealer at the base of the grosgrain (interior) would not hurt.
John