I had a pair of Monroes on the rear of my track car 33, and tried them back to back with Konis on the track.
The Monroes are a perfectly good substitute for a standard shock, but the Konis made the car a lot more controllable over fast bumps, and are certainly worth paying a bit more for if you value performance.
If performance isn't critical, the Monroes are fine on the road for most non-alfa drivers. For those with "Cuore Sportivo" syndrome

then the Koni or Bilstein options would certainly be preferable.
Cheers
David F