Yes, I have a Holley Sniper 850-550 on my 300.
I'd had a 4bbl carb on it for years, so I wavered back and forth between going with the 4bbl Sniper or the 2bbl Sniper, but was then advised by both forum members, and Holley, to go with the 2bbl setup since it's rated for 350hp (which is plenty for me) and flows 580cfm. Unlike a carb, it doesn't depend on air speed through the venturi to get crisp throttle response like a carb does, so a "big" 2bbl design works just great.
I very much like it. It fired right up from the first turn of the key, and has been a joy to drive since. I've never had such crisp throttle response. Plus, the cold weather options and drivability leaves the carb to shame.
I also love all the data I can read and pull up on the handheld. Engine vacuum/pressure, AFR, coolant temp, air temp, RPM, throttle %, fuel flow rate, battery voltage, just to name a few, as well as the data-logging to view and look over later.
For the fuel system, I used the system from a '85 302v8 since it was fuel injected, and in my body style / era.