The other model to add to the discussion is the Barbell Strategy created by Nassim Taleeb. Put 80% into something totally safe and put 20% into something extremely risky. That can have the same risk profile as the single investment you describe but offer the chance of disproportionate returns when (if) the risky investments performs
I think this is noteworthy of only this case or ones within the vicinity. Regardless of what percentage of risk there is, it is still a risk, and the degree of this may or may not be compatible with every investor's profile.