- rods are better for uplift. Architects sometimes object however in those cases, I've used light duty moment connections at the low wall connection and just let the rods buckle out of the way.
- depending on your code and geometry, you may need to deal with snow blown onto the canopy from the adjacent roof.
- I usually make the low rod connection a gusset plate that's tall enough to get the connection safely above the roof assembly to make roofing the penetration as easy as possible.
- there's often a gutter that your framing needs to dance around.
- if aesthetics are important, I'll sometimes use a post installed connection at the top. Cast in plates have tolerances and they can be mislocated or rotated in ways that catch the eye.
- use materials suitable for outdoor exposure do that you don't get rust bleed all over. This can often be a issue at the cast-in plates.
- if possible, I'll provide field adjustability in the rods. One way is turnbuckles but those can be visually obtrusive. I've often used a detail where a bent plate is welded to the upper connection plate. A threaded rod passes through one of the legs of the bent plate and a pair of nuts. It's pretty clean.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
