5hr 45m Transit Time-Enough to leave airport?
 

I'm looking at flying MIA-SVO-FCO with a 5:45 connection in Moscow. We would like to get out of the airport and see something during our short time in Russia if possible. Inbound is on Aeroflot, connection is on Alitalia. Would this connection give us enough time to get out and see any of the tourist sites?

Probably not. It's an hour each way to the city by the train (5-10 min walk + 15 min average wait + 35 min ride). The Kremlin is 10-15 minutes away from the rail terminal, but still you'll have close to zero time there. Now if your inbound flight arrives an hour early and/or you're comfortable with arriving at the airport 1-1,5hrs before your flight rather than 2hrs, then going to the city is fine.

P.S. I assume you've got a visa or a passport allowing visa-free entrance to Russia.