drawbacks to inconel valves?
 

I'm refreshing my motor for the season and I would like to learn a little more about inconel valves.

Specifically, if there is a down side (in the form of rapid wear, servicability, ect.) Is there any set-up differences in valve seat width? or with stem/guide tollerences? or preferences in guide material? Since they have a different expansion rate than SS, is the valve lash set differently? Are they soft like titanium and require lash caps?