[mvonfr]

I understand this.

But S-400 are not the latest, and while the Chinese are likely capable of manufacturing clones within a few years, the US is not.

Let Putin figure out the risks/benefits ratio, he does it better than we can.

[PIF]

S-500 Prometey is the latest, but are not operational yet. So the S-400 Triumfs, aka SA-21 Growler, are the latest. How effective the particular S-400 system is depends on which fire-control system is coupled with it.

The S-500 will significantly out class the S-400 with 6th gen radio comm and many other features.

See this Tyler Rogoway article on the S400 system (Tyler has since left the site he founded for a job at Time and the site has gone downhill since).
http://foxtrotalpha.jalopnik.com/heres-russias-s-400-missile-system-in-action-and-heres-1746490022

[amorphous]

From a twitter feed, we had a couple of F22s in the area on day two, which supposedly chased away some Syrian fighters. I'm wondering how well they will fare against the SAMs?

Better than anything else I suppose. :-)